Poncho Revival -- Building a Stroker Pontiac (Secret EFI!)

Keith Dorton of Automotive Specialists takes a junkyard 389 block (with missing main caps) and turns it into a 416 cubic inch Pontiac V8 with the classic triple-deuces look except with trick modern fuel injection. Please note: In the video I call the block an original 389. I think this is actually a more modern 400 block. Sorry for any confusion.
Engine Builder: Automotive Specialists www.automotivespecialists.com/
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[@soulsofpresentgracethompso5990]

Keep the Poncho power flowing.

[@TheMrmmkkpro]

Very nice, I have drag raced Pontiacs since the late 70s. I currently am running a 1972 455H.O, bored 60 over trw L2394 pistons and with the 7f6 heads. A nice healthy comp cam, torker 1 and a 850 hp series carb and a msd ignition. This engine runs great makes a lot of torque. Thanks for posting this, keeping the poncho alive. 👍👍🏁

[@johntempest267]

That torker 1 is pure gold. Unobtainium. Victor Jr. is all we have now, an intake design that runs counter to Pontiac characteristics.

[@iceman45ification1]

In an age where all you see is LS1's, it's great to see an old school engine. Always loved Pontiac V8's. That Tri-Power fuel injection setup is pretty sweet, although the power did get sacrificed a bit. An 8-stack Kinsler fuel injection would've been cool too. Great video sir!! 😃👌

[@moodybluemotorsportsDwneKnos]

I totally agree with you, seems as if ls engines are in everything nowdays, I do love the power advantage and easy to find but it's nice to see old school power as well. I've never seen or heard of what I'm planning to do but I'm seriously thinking of doing a Pontiac stroker engine in my 1968 Chevelle smalltire street raced style car. I'm an old school Chevy guy but believe for racing the Pontiac has advantages over sbc and BBC.so that's the plan !

[@iceman45ification1]

@MoodyBlue Motorsports hell yeah that'd be sweet! 👌

[@freddypayton503]

No doubt. Definitely good to see a Pontiac on the build

[@davelowets]

There nothing wrong with an LS... back in the day, the pontiacs all had boring pontiacs in them... gay.

[@iceman45ification1]

@@davelowets different strokes for different folks. 🤷‍♂️

[@IronChief]

389 and 400 have the same main journal size. 421, 428, 455 have the larger 3.25 size.

[@TheHorsepowerMonster]

Correct. I definitely could have been more specific there that the 400 has the smaller journal too. Thanks for watching

[@stevehicks8944]

Yep, 326 and 350 have the 3.75 inch stroke and 3.00 main bearing size as well

[@thomascocchiola7214]

389 would have 2 freeze plugs and only 2 motor mount holes that block has 3 freeze plugs and 3 motor mount holes making it after 1977. 1966 and earlier blocks had 2 freeze plugs on each side of the block. 1967 and newer had 3 freeze plugs per side. These blocks had 2 motor mount holes per side.Starting in 1970, most blocks were cast with 5 motor mount holes with the mounts using 2 bolts in line with 1 higher up in the middle.Some 1977 and later blocks only had 3 holes that used the newer mounts.

[@adampatterson707]

I had a 64 Catalina with the 2bbl 389 with a 3 on the tree. It was a early 64. It had right and left cylinder heads. The heads were oiled from passages that came from the thrust bearing. It was a great car, I still kick myself for letting that car go. Keep up the good work. Thanks.

[@Brock_Landers]

Wow, this is a beautiful build. I have always wanted an early GTO with a fully built 389 or 400 with a high compression, snappy response, lopey cam engine. This tri-power build will serve that wagon well.

[@davelowets]

Why not a 455?? Go big, or go home...

[@tedsmith3061]

Been working on these old cars when they were considered almost new. I absolutely LOVE these builds. They are historical reference material. Listen carefully...learn a lot. Keep making these videos. Please?

[@philipmazzuca2269]

Intake/carb/TB is killing that engine power wise............ Dortons are amazing......... fantastic build.

[@boston7704]

Yeah, but damn does it look cool. :-)

[@davelowets]

It's a driver, not a race car

[@kevin2960]

But there are aftermarket tri power intakes, I believe Kaufman is the best.

[@lars277]

When I see this man at work, it is a marvel to watch his experience expertise.

[@glennwallace607]

I remember seeing this six pack on a 64 GTO. I was in love with it. I did get my six pack but on a 68 Roadrunner. Would pass anything but a gas station.

[@blainesnider9089]

If progressive linkage and your foot out of it it should have gotten ok fuel milage but in it would drink it for sure

[@bradleysample3246]

We call it tri power.Six Pack is Mopar talk

[@rafaeltorres2886]

Wow sitting back and watching this build come together is ❤ The only thing to make it a bit sweeter would be a quarter mile run at the end , with a time slip.

[@phillipthethird42]

I'm a pontiac guy and it's always nice to see what guys are doing with them. It helps me to keep on top of the latest stuff. Thanks

[@jw4620]

Marvelous oldie! Built for fun and show, so it doesn't need to be maxxed out.

[@davidtucker3729]

love that retro intake setup with the EFI I can never afford. Sweet. Go Pontiac power!!!

[@jareknowak8712]

As usual, very informative and clear. You're doing a great job with these videos!

[@TheHorsepowerMonster]

Thanks very much!

[@prtyof4156]

Love the unique builds featured, keep it up!

[@TheHorsepowerMonster]

Thanks!

[@genelong1748]

I bought a 1966 Pontiac Catalina from my Grandfather. 389 tri- power. Central Texas was glad I stopped street racing. Best all the cars in the 70's and 80's

[@Draxindustries1]

Quality engine build and love the pontiac estate car..

[@ecrusch]

LOVE this channel! Horsepower rules !!!

[@TheHorsepowerMonster]

Thanks a lot!

[@freddypayton503]

Great build peeps

[@vortexgen1]

The original Poncho Rochester 2GC big base Tri-power carbs flowed 325 cfm. Those T/Bs being bolted on are for the Chevy Tri-power being retrofitted to the Poncho, because the offset T/B hold down bolts. Just like you said, those Rochester 2G small base carbs flowed 285 cfm for the Chevy stuff. A single plane intake works great for WOT, but is less effective for driving on the street. With this street friendly setup, the owner will be much happier driving around town.

[@michaelparadisis4076]

Great video as always. Thank you Sir

[@TheHorsepowerMonster]

Hey thanks!

[@manitoublack]

Would love to see quad webers on one of these🙄. Oh yeah. And this is totally awesome as is😁👍

[@jareknowak8712]

I would love to see 8 injectors on one of these :)

[@skylerb7103]

Great video!! Keep it up!!

[@TheHorsepowerMonster]

Thanks! And thanks for watching

[@louf7178]

Good to see!

[@hotrod6919]

Damn! love the 3 deuce hidden efi setup, saw a guy put hidden efi on his goat years ago. basically he turned an old carter afb into a throttle body with jb weld and rest setup from a early 90's chevy pick up Looks like a Duramax head in the background

[@jp2246]

That is a gorgeous wagon

[@margaretwrein9606]

I like the whole presentation on the build.

[@TheHorsepowerMonster]

Thanks a lot! And thanks for watching!

[@tonyschiffiler4816]

Would like to see more about oil clearances . small rod specs. and piston to head clearances , beautiful build by a pro thank you .

[@WhiskeyDale]

neat set up

[@markwallace5274]

Love them Pontiacs !!!!

[@tomschweikert9537]

pontiwac!

[@user-hk5ji5ws9d]

Great Video

[@TheHorsepowerMonster]

Thanks a lot! And thanks for watching!

[@UnityMotorSportsGarage]

I love your video style... I would like to get up with you about that Progression ignition system video you did... Thanks for your hard work Andy

[@TheHorsepowerMonster]

Thanks for the kind words, and thanks for watching!

[@2HacksGarage]

Subbed 🤘🏻🤘🏻🤘🏻 poncho power!

[@TheHorsepowerMonster]

Thanks!

[@SweatyFatGuy]

The intake and cam are why it didn't go over 550ftlbs and 500hp, the cam would work better with the RPM or a single plane like the Torker II. If he dropped the cam to a 230/236 solid roller with a 108-110 LSA it would pick up torque and carry it farther out making it over 500hp. You can get over 550/500 with unported RPM heads on a 461, you can do it with worked 250cfm iron heads too. The intake starts to choke the flow above 3500rpm, Tri Power intakes are just gonna do that. The cam is killing some grunt at the bottom and the intake isn't letting it make torque farther up. However... in a 55 Safari show car, it is more than enough. I know how well an engine around that power level will hook on street tires, especially the kind you'd run on a 55 Safari. It won't at anything more than half throttle until its over 50mph. It will sound mean as hell at idle with that cam, it makes plenty of power despite not making the most of what its capable of, but the EFI will tame the lope a bit, still it will have what hoonigan calls chop. So perfect for a show car. That engine is VERY overbuilt. Forged bottom end, solid roller, MLS head gaskets, splayed four bolt mains.. I mean if you can afford it, why not? It has better parts than my 700ftlb/700hp two bolt 467 does. Change the oil regularly, get it warm enough to boil condensation out of the oil, keep it under 6500rpm (Tri Power won't support 428ci or larger over 6000 anyway) and it will live forever in a daily driver.. that runs 11s. If he stepped up to an IAII or MR1 block he could then throw boost at it and make 1500-2000hp real easy, all the hard parts are there except the block. The old 389 blocks are tough though, they can handle more than the later 400 and big journal blocks. Not that its even coming close to the limit of the block as it is. All in all its a cool build, kinda like the 461 in my 68 LeMans, but it has a 240/244/110 flat solid and unported E heads. Wish I could swing all the forged and high end stuff in all of mine, but I have too many cars to do that.

[@TheHorsepowerMonster]

Great points. Thanks for watching!

[@edbartone3869]

This is a very good comment. I built a 461 stroker as well, and I used a performer rpm dual plane with a Well worked Quadra jet. My cam is a 236 / 242 at 112 LSA. This engine makes just under 500 hp at 5,200 and 600 foot pounds of torque at 4200 RPM. Get this, I used stock number 16 heads that have not been ported at all. It is a bit of a shame to see all the effort and cost that went into this engine, to then throttle it the way it did with the induction system and unfortunately over sized cam. It did have quite a bit more Potential. Even so, I enjoyed the video, and love Pontiac’s! Any time I see someone creating a Pontiac video I must applaud. Thank you!

[@dennistate9951]

Great video

[@TheHorsepowerMonster]

Thanks a lot

[@hcolin4165]

SaaaaWeeeet Poncho Amigo!!!

[@billbarnes391]

Very nice

[@williamklein1221]

Pontiacs use 2 tubular "dowel pins" to locate the timing cover to the block. These are at the 2 lower timing cover bolts.

[@edbartone3869]

True, but be careful, if your block has been line board or even lined honed for the crankshaft, it will no longer be centered with those dowels, so will then require you to you do what he did to adjust. I did the same with mine.

[@jedidethfreak]

400 block has the same 3" mains as the 389.

[@paceta80]

That's a gorgeous Pontiac engine. I have a 1972 Pontiac 400 that I'm going to have built for my 1980 Trans Am. I'm not a fan of the blue engine paint though. The silver on this one looks great!!

[@davelowets]

Paint it whatever color you want... 🤷 A 1980 T/A never had a poncho 400 in it anyway

[@scottmeyer6005]

Soooo Awesome That thing makes more torque @ 3800 than most engines make power!

[@jhutch1470]

Wanted to mention that you said the heads were 72 cc. That would be with the 3.75 stroke crank. The heads he used for the 9.7 comp ratio were 87 cc. Nice video, and nice build.

[@QueenCitySpeedShop]

Keith is a freaking genius.

[@TheHorsepowerMonster]

You are correct. Thanks for watching!

[@nadronnocojr]

The dr is in !

[@barryfields2964]

I would like to see a before and after of the flow numbers of those heads.

[@CrankAddict]

so sad about that intake system. that cam should have made max torque close to 5000 rpm. A victor jr would have done wonders for hp. That tripower intake killed it! I've never seen a dyno run without the waterpump not running. How does that effect timing due to hot spots, etc?

[@geoffmooregm]

The dyno must provide the flow. It is an impeller pump so the water can flow right through with just a little restriction.

[@oldschooltwist18]

I used wenzler heads and tunnel ram. Wish I had known about Molnar when I did mine. They have awesome stuff. Glad to see them used. I have forged star galaxy rotating assembly. My compression is higher at 11.71 as I'm on e85 w mark sullens carbs. Love the build!!!!

[@davelowets]

Good man.... using a stretch guage for the rod bolts. 👍 Way too many people DON'T do this.

[@philipmazzuca2269]

Very nice linear power

[@jamesdiehl8690]

The man who knows flathead inside out!

[@levibrock5570]

I have a 74 455 in my 65 Lemans . Its stroked to a 468 I have a 750 dbl pumper on it now. I also have a 65 389 Big car engine With a factory tri power on it 068 cam 4x Heads . I would love to do what you did in this video to my 389 and use my factory tri power. Cool video super informative . Pontiacs rule

[@francfurian8215]

That man is meticulous & knows how to work an engine. Awesome! Cheers😊

[@TheHorsepowerMonster]

You are definitely correct. Thanks for watching!

[@brianlee6849]

Awesome 👍. If you were building a for a trans am with a shaker hood what intake and fuel injection would you choose? And have you built one of these in the past and what did it dyno ? I'm interested in doing something very similar to what you built here for a trans am. Thank you

[@edwinyoung2719]

I’d be curious to see what a modern day aluminum ram air V head would do versus one based off of the ram air IV…. From what little I know of poncho’s the ram air V seems like a better way to go

[@LT3Fluffy]

A little disappointed that this is going in a show car never to be wrung out. But a killer poncho build nonetheless

[@jessemurray1757]

I bet Keith wasn't too happy about switching the intake LOL. Customer gets what they want though.

[@christophermclaurin7479]

Hope to work with you guys soon

[@curvs4me]

Sweet torque monster

[@242bleek]

That flat inner valve spring will eventually eat up those fancy titanium retainers.

[@TEH47]

Nice and reliable Pontiac engine build, to bad you didn’t have the time for some dump pulls with a RPM or old Torker intake

[@fabieneldridge3414]

Nice engine, it should make the Wagon Rock !

[@coreylomeli1667]

I need this so bad

[@SOU6900]

Only time I've seen a 2 barrel Rochester in the wild was in a junkyard sitting on a small block Chevy in a 84-86 Suburban. Wish I had grabbed it...

[@davelowets]

Why??

[@vannjunkin8041]

How many horses do you think it left on the table with that efi set?

[@timewarpvideo6244]

Forget the station wagon. Put it in a Trans Am!

[@thebigpicture2032]

TriPower doesn’t really fit a Trans Am. You have to lose the shaker or make it extra big. Station wagon works for the cool factor.

[@chevydyall7619]

You should have far more than 70k. Im trying lol. I like every video I remember too lol

[@TheHorsepowerMonster]

Hey thanks! Very much appreciated!

[@markhensley9378]

Great video! Pontiac engines make awesome power!

[@TheHorsepowerMonster]

Thanks for the compliment. And thanks for watching!

[@johnsmith-qz4bv]

nice like those throttle body carbs....

[@Clobercow1]

Pretty aggressive cam for the intended use eh?

[@davelowets]

No

[@snodgress137]

How come nobody ever mentioned the 326? I have one in a 65 lemans are they junk engines or what? Thanks for the build!

[@billygoat1708]

A couple things don't add up in this video. First, 389 blocks had 2 freeze plugs per side. This block has 3 freeze plugs per side which was on 400 blocks. Second, 72 cc heads on a stroker (455) are not going to give you 9.7 CR. Need about a 94 cc head to get 9.7 CR.

[@davelowets]

All depends on the piston and head gasket used. Plus deck height and how far in the hole the piston is.

[@garyross1279]

Cool

[@marksgarlata9286]

Pontiac Power !

[@danielsosa3562]

What was the LSA on camshaft

[@dadfood3504]

GTO Goat

[@shawnbaird2015]

Nice fuel injection system👍

[@SGTJDerek]

I love how he doesn't go hog wild on power. Always seems to achieve balance between power and longevity.

[@davelowets]

Whats wrong with hog wild on power?? 🤷

[@SGTJDerek]

@@davelowets 🤣nothing for others but for me it comes down reliability.

[@hydroy1]

4 bolt aftermarket caps , forged crank, H beam rods $$$$$$$$$$$$$$$$$ no budget on this puppy .

[@hydroy1]

All that for a motor there only twisting under 6,000rpm, what a waist. With that crank, rods & caps that puppy is not even working until 7,500. rpm. and really over 8,000 would not be a issue with the right cam & intake. In my opinion, that short block is scramming for pair of aluminum aftermarket ram Air tunnel port Vs !

[@TheNumbers400]

min 13:15 When you see it....... LOL

[@lostallmymoney2082]

Your title on the video says 416, not 461. Hope this helps sir.

[@TheHorsepowerMonster]

Oops! Thanks very much!

[@trashbandit2449]

So does the description

[@AceHardy]

✍️

[@jareknowak8712]

My God, i miss Pontiac :( I love 3rd gen Firebirds.

[@davelowets]

3rd gen.... 👎

[@sullie35]

Where is them Lifter bore braces?

[@remybrouwer8700]

Seems that the damper was moving eccentrically, bend crank, damper defect , or is it the sticker that give that effect ?

[@SweatyFatGuy]

just the sticker. A crank bent that much would wipe the bearings real fast.

[@canabox7112]

That intake is ridiculous.

[@indyrock8148]

I noticed Keith didn't weld the adjustable guide plates? Is this correct and he doesn't do this? I am asking because I need to fit some to my engine. If Keith doesn't think it's necessary to weld them then I won't either.

[@the4flatgarage]

I tig weld them in 3 places.

[@Motor-City-Mike]

We ALWAYS tack weld them

[@ericthompson3551]

Description above says 416 but I’m sure you meant 461.

[@Lennyp4]

can’t believe you got 500horse 550ft/lb out of that thing

[@johntempest267]

Can't believe? These numbers can be exceeded with factory junkyard heads and a Holley carb. Good build, not extraordinary.

[@arthurdombroskie3083]

How do we get 9.7:1 on a 461 with 72ish cc chambers and flat top pistons?

[@jareknowak8712]

1:15 - flat top with big valve pockets.

[@thebigpicture2032]

I was wondering that as well. They do have deep valve reliefs and a few cc’s ported out of them but still seems a bit low.

[@jareknowak8712]

461ci = 7,550 ccm 7,55L / 8 cyl = 940ccm chamber should have little less than 100ccm, for 9,7 CR. All approx.

[@CrankAddict]

Thick gasket and crappy quench.

[@kellynestegard5208]

With a .040" thick gasket and 14 cc dished pistons that are .060" in the hole.No wonder it makes shitty power.

[@Brock_Landers]

I had a dream the other night, I was driving a really small domestic pickup like a Chevy Luv or an old Dodge Ram 50 with a large displacement big block 632, 572, or even a Sonny Leonard engine that was so snappy that with a 4 speed manual it would INSTANTLY light up both rear tires and take tf off. Now THAT would be my dream build. I'm willing to bet that a Ram 50 with a well built 360, 400, or 440 would get the job done easily. ESPECIALLY if it's a Dorton engine...😉

[@dustybyram8849]

My wife 68firebird has a 474 600hp 600 ft tq.

[@w41duvernay]

WISHED these guys could have built a 428 out of a 400 Pontiac.

[@55classic1]

they could...simply have to cut down the mains to 3"...if they can use a 455 stroke they can surely use a 421/428 stroke

[@davelowets]

Why? More cubes is better... There's nothing magical about 428 cubic inches

[@Aladinscave]

Run it on a four barrel setup just to see what it’s got?

[@TheHorsepowerMonster]

That definitely would have been interesting, but we didn't have an intake manifold to fit a four barrel carb. Thanks for watching!

[@chrisgarringer9133]

It flows to a certain extent, but Its almost like having a restriction plate, EFI ,YES! Butler Performance and Injectors tapped into the intake bugs and this is a different kind of animal. all the head porting was a waste.

[@TbsDltn]

nice restomod ponch small block v8(wink,wink)...

[@coreyrowe2052]

Is his name Dorton or Norton?

[@TheHorsepowerMonster]

Keith Dorton. Thanks for watching

[@GJ-DT]

Stroke a 455 with victor and 850

[@yugotime1598]

Hur durrrr I gotta have the tri power cause muh history says thems good fer power.

[@turbotempest4095]

I thought 389 block's only had 2 frost plugs per side.

[@TheHorsepowerMonster]

You are right. I mis-idendtified the block. Thanks for watching!

[@garyduncan6820]

Should have used the Pontiac big chief heads

[@davelowets]

They don't FIT on this block... 🙄