Identify and Choose a Slant Six Cylinder Head

[@abarguy]

I’d like to clarify your opening statement. The slant six was developed in 1958 and first hit production in the 1960 model year. First engines were the 170 and 225 concurrently. By the late 1960’s, the 170 was replaced with the 198.

[@talljohnsfunshop2722]

One advantage to 75 and newer head are flame hardened exaust seats for unleaded fuel

[@brianjuffs4662]

You should remove the crush washers, that's what the tube is for.

[@YoshimoshiGarage]

Yes, good call. I noticed this core head still had them, too. Having the crush washers actually pulls the plug back into the head a little bit and makes then run a temp range cooler as well, which is usually not what you want.

[@bryandickerson5365]

@@YoshimoshiGarage More good info. I’m contemplating building a Valiant with a “hot” slant-six. Nothing crazy, but hoping to get a good combo of performance and mpg. Planning on 5 speed to help with mpg. Any recommendations on building a 200+hp S6 capable of 25+ highway mpg (w/ overdrive)?

[@sparkplug-ne5wi]

1965 heads with the cups i take off the crush washer because you have the cup

[@Carlos-hn8mu]

My slant six head is stamped with the word special.this must mean theirs tree different heads.

[@stevereid6088]

That is a very rare head as it's for the aluminum block. There were only 55kish of those blocks made

[@reallyaintbuynit2018]

I just watched Steve Magnante's video last week after he found an aluminum slant in a wrecking yard and he pointed that out.

[@rcnelson]

I still haven't seen what the "peanut head" slant six chamber looks like. Thumbs up for the video, though, which was informative.

[@bryandickerson5365]

That’s good stuff - thanks!

[@bruceroberts1404]

I have a head that is different from all that I have seen My slant 6 head uses 5/8 plugs, but has NO smog ports at all. My guess is this is a late 74 head if in fact the smog port started in 75. The head at this moment is still on the car and I do not have casting numbers yet. I am about to do a valve job on this engine. Its in a 74 Duster, but I cant confirm that this is the original engine yet.

[@markfortin421]

What about the early aluminum block cars. Did they use one of these heads, or did they have a special head, with possibly performance tweakings, or just standard heads from the cast-iron block. Thanks for opening a can of worms...I've always loved the slant 6.

[@stogierun6978]

81-87 slant 6 Hydraulic Lifters and the Valve cover was different.

[@leecrt967]

0:26 The 198 came out in 1970. It replaced the 170.

[@raywilson1679]

after reading the comments,I noticed some people are not aware of what the tubes for the spark plugs are actually designed for.

[@YoshimoshiGarage]

The comments section of just about every video seems to be where some people have to prove they know more than me. They could just scroll on, or even make a video of their own but no, the comments of videos with a very small viewership is where they feel they can best shine. Good old Internet.

[@normp3273]

Too bad there isn't a company that makes performance heads for these engines. Steve Dulcich burned through a few water jackets on a couple heads that he was porting for his slant six. I believe he was prepping that engine for the engine master show. He had a torque storm supercharger and ended up blowing a head gasket. I forget what the power numbers were but they were really decent.

[@michaelware7294]

Great info

[@kennethcohagen3539]

A friend took a set of spark plug tubes, got 2 more of them and used them as boot protectors to keep the headers away from the plug wires. I think that would work if the tubes were wrapped or the headers were wrapped along with the tubes. Anyone try that? By the way, back years ago some guys called the slant six a half Hemi. The slant of the block looked like half a V8, ( to those who have trouble counting), and the Hemi used spark plug tubes like the slant six to be able to put them in the middle of the valve cover.

[@tommyreid2317]

198 replaced the 170 in 1970.

[@ppdntn1]

The 198 was made well after the 225. You already have shown your ignorance, why should anyone trust your supposed "knowledge".

[@YoshimoshiGarage]

Can you hear my eyes rolling? The amazing thing about KZbin is that if you don't like something, you can go watch something else. I probably care less about your opinion than you do of mine, so move along keyboard warrior.

[@liberaltears6328]

What is the best slant 6 head. Cast number? I want to do a torque storm supercharger. Thank you

[@YoshimoshiGarage]

I'd follow Dutra's advice of 1968 or later heads. It's worth noting his torque storm build used a pre-75 head (it has spark plug cups), so I'd look for a 68 or 69 to 1974 head. www.slantsix.org/articles/combustion-chamber/sl6-combustion-chamber.htm