A brief commentary on Mopar LA 360 heads, and a quick look at the intake ports.

In this video, I take a quick look at the Mopar 360 J head ports, and share my opinion on them.

[@edsmachine93]

Great video, you are absolutely correct on using the 340/360 heads. I like the J heads and the X heads. The J's are more plentiful as compared to the X heads. But they can be built to work just as good. The 1.88 can be used on a 318. Things can be done to increase the compression. For the guys watching this that are 318 guys, 2.02 heads can require bore notches on the intakes depending on valve lift, deck height. While I like all the new type technology heads, but I am and always will be a stock block guy. There is room for both in my mind. Nothing wrong being a purists. While the Magnums can be a Performance advantage, they can be prone to crack. And very hard to beat a Rocker shaft assembly. At the end of the day, there is alot of good in a Mopar small block. Thanks for sharing. Take care, Ed.

[@MrSwinger1]

Thank you. I am hoping to get the info out there on what the actual differences are between the LA 318/ 340. I've heard it all through the years people would say " a 340 is a 318" a 318 can do what a 340 can do" etc. While the latter may be true, but with a lot of modification. Having been through both engines more than once I do beleive the 340 had unique " internal components" that folks are unaware of, and that may be overlooked.

[@MrWill73]

I hit the bell so I know when you make a new video. I’m following Nolan’s Magnum 360 build and will be following you working on your 360. I’m soaking up tips on engine building so when I dive into building the Buick 350 out of my dad’s tribute Lesabre I have solid tips and techniques. I am going to build it from top to bottom. I always send out my bottom ends or a complete motor to my engine builder but this build is very special to me so I am going to do it all myself.

[@MrSwinger1]

Thanks! The key thing IMO is knowing when you need a machine shop. It really is a series of measurements and checks. With this build,I did send the forged crank out,but by measuring the ring gaps,I've decided to hone and rering. My decision there is based on it being a 340 block,and trying to get the most out of it before over boring it. Basically save it for the next guy to possibly go .030 over with it. I think folks go over bore sometimes even if they don't have to,or they go way over,.040 when they could have went .010 for example. I do have another 340 that is in my car thats .030 over.

[@dynodon100]

If you put 340-360 heads on a 318 you will lower the compression as they have larger combustion chambers . You should upgrade to popup pistons like UEM-IC845-030 That will work well.

[@MrSwinger1]

I was going to do that once when I was younger put J heads on a 318 stock bottom end. An older mechanic I knew advised against it for that reason lowering compression. I stuck with the stock heads. The 318 ran ok it wasn't all that in the top end though.

[@happyhermit6899]

The exhaust ports are the limiting factor in these heads. 318 heads have a better shape on the exhaust. Also. A substantial compression gain is had with a 318 head.

[@ahoneyman]

The X head is a no doubt slam dunk head. It's great. The chamber volume is the right size for good compression, great intake flow, and just an all around winner. The 360 heads have gargantuan chambers so you lose 0.5-0.75 points of compression even with aftermarket pistons. That means milling and custom rockers. The 318 heads will run out of steam at 5000ish RPM. Is that a huge deal? On a $2500 build not really. The crank and rods aren't good for a lot more anyway. On a $5000+ dollar build all the stock heads are going in the trash.

[@MrWill73]

Hey Mr.Swinger, great video! Great solid info on the 360 and 318. Plus, have to ask, your engine is spotless! Did you clean it yourself or is it fresh from the machine shop? Definitely would like to know how you got it that clean if you did it yourself. Take care👍👍👍

[@MrSwinger1]

The heads were disassembled and glass beaded years ago,but they are 360 heads with 1.88 valves so there are a few things about them I'd like addressed. The guides are knurled, so I'd like new guides or bronze sleeves installed and I'd like to have hardened seats and 2.02 valves installed. The block,I used evapo rust on the outside,and a combination of wire wheels,electric sanders and air tool polishers along with steel wool,scotch Brite and carb and brake clean. I used a 2 stone jone on the cylinders,they arenr perfect but I beleive the rings will seal. So yes alot of " scrubbing " its a dirty job but like said you need to take measurements so it needs to be clean enough for accurate measurements.

[@blairlindsay5791]

explore the potential of the small port , high velocity 273 closed chamber head ? or #302 swirl-port rebuilt with 1.88-1.60 ?

[@MrSwinger1]

I'm not very familiar with them however, if I was running or building a 273-318, I would consider them for the compression charachteristics.

[@anthonysoulard9938]

Combustion chamber is way bigger too , put that thing on a 318 and you'll end up with about 7:1 lantern oil burning compression rqtio

[@brotherjesus4246]

Exactly! The point that everyone who reads your post might miss is just this simple little fact. DON'T BUILD A 318, WHEN THERE ARE CHEAP 360 OPTIONS AVAILABLE ALL OVER THE DAMN PLACE! 😂

[@anthonysoulard9938]

@@brotherjesus4246 you can build a decent 318 that will live longer than a 360 but you gotta know your game

[@4Serviceplan]

I am struggling to just use my j heads bronze wall harden new valve polish as much as possible. Can I push 450 to 500 affordably

[@MrSwinger1]

By 450 to 500 do you mean cost or CFM on a flow bench? If cost I think that may be close,it goes up if you factor in the cost of buying the heads, it may for example cost 500 for machine shop work. As far as flow or CFM I don't have much experience with that but,I've never heard them flow that high they usually flow in the 200 s and that's with 2.02s and bowl porting work. I have those heads in the machine shop now,I'm keeping the 1.88s and getting valve guides installed. I will post a video on cost. They've been there going on 4 weeks now so its a slow process requires patience...:)

[@blakenorman4822]

Im putting some 74 la 360 heads on a 72 la 360 block, are there any emmisions crap that will hurt my power on that setup? thans for vids

[@MrSwinger1]

You shouldnt have any issues with that combination. The heads should be very similar if not identical in performance except for casting number the 915s are 70-72, 587 is 73-74 360.

[@blairlindsay5791]

I’d rather cut new seats in the 1.88 head . Enough material to work with for 2.02”-1.625”. New iron guides and oblong the pushrod holes . Take your port & polish as far as time allows

[@MrSwinger1]

I ended up sending out my 1.88s for a refresh and some new guides. I still have the 1.88s in them though...I have the 2.02 set to send out next. It was $500 for the 1.88 J heads to get work done. Not alot of money really by today's standards. If I punched them out to 2.02, then the cost of the valves factors in, it my have been closer to $ 700 Either way I have a set of heads ready to go...I may hold off for the 2.02's for this build ,sometime this year Ill contact the machine shop, they guy is really busy and it takes a month or so to get my spot "in line" to get work done.

[@blairlindsay5791]

@@MrSwinger1 my motorcycle pals introduced me to the newway seat cutting tool . your old 1.88’s are the foundation in building a pair modified 318 heads , to follow

[@MrSwinger1]

@@blairlindsay5791 I have been looking into the Neway seat cutters ffor my 2.02 set,I need valve guide sleeves also. Id like to get the equipment,it will only get exprnsive paying machine shops in tne future I beleive.

[@blairlindsay5791]

@@MrSwinger1 I’ve learned not to expect blueprint precision from anyone but myself

[@antisocialsecret7584]

What cam will you built on..spec ?

[@MrSwinger1]

I have a SUM K- 6901 sitting ion the shelf with the following specs. Duration 276/288, Lift .441/.441 Flat tappet. I was kicking around the idea of a 68 340 manual trans cam regrind from Oregon Cams but I need a Core. I do have a Crane SSH-320 sitting around also but that is a lopey idle cam. I'm going for stock/streetable or as a 340 would have been in 1969-70 in a street car.

[@antisocialsecret7584]

@@MrSwinger1 Around 10years ago, i buy one cc xe295hl ,hydraulic flat tapet..still not use that cam. Instead i stick in a cc 275deh in my then car..good cam. The big cam, must have heads who can flow 280cfm..singel plane intake. Looking for a dodge dart -68 -69. They cost around 20.000$..not top shape. Sweden 🇸🇪

[@allanfranco4464]

WHATS YOUR POINT KEEP REPEATING YOUR SELF TELL ME SOMETHING WE DONT KNOW

[@MrSwinger1]

Yeah yeah yeah...I will keep repeating myself over and over and over and over and over and over and over and over and over and over and over.....

[@MP-pz9oe]

All LA heads have good intake ports, the exhaust ports are a disaster .