best head choice

[brandonwortley]

I have eight heads to pick from and need help choosing, a pair from and 82 C engine, a pair from a "J" Van (I think) a set of c heads from a van and getting the cracks fixed in my 86 c truck heads. What is the best choice? ( I have a fairly large stockpile of parts that I have accumulated)

[britannic]

Go with the J heads. I think the van heads are slightly different with the angles of the injectors and possibly the bolt holes - so do check and hopefully somebody else will chime in here with the correct info.

[brandonwortley]

So I am guessing that there is quite a difference in the c and j heads? different precups? bigger valves?

[brandonwortley]

So I am guessing that there is quite a difference in the c and j heads? different precups? bigger valves? Is there a way to distinguish between the two heads, numbers etc?

[Stage1]

FYI,

From reading the build-up on Docs engine he selected a late 90's ( it may be a 97 or 98 model year)non turbo 6.5 head, the article mentions the benefits of the precombustion chamber design for this head.

Suggest reading the complete description of this engine build-up, available here on DP, for a lot of excellent knowledge.

Les

[grape]

82 heads with the j chambers.

[britannic]

One caveat: the early heads used a coarse thread injector, which are getting more and more scarce and preclude using the better performance 6.5LTD injectors, unless a rebuilder can do some custom work on them.

[big swifty]

I have a pair of low milage 6.5 turbo heads that never made it onto my project truck if anyone is interested.

[Craig M]

The early heads get better fuel mileage if that is a consideration. We get 22 mpg freeway on our half ton 82 Suburban.

[brandonwortley]

sorry it took so long to get back, are the 82 "red" heads high nickel like the block?
I think that they are in the best shape but I am going to have them redone regardless of what set I use. I use a good engine guy that will do them for about 80 bucks (I think that is each but not for sure) valve grind and new seals, maybe new springs too.

[brandonwortley]

also how do you tell the difference between J and C chambers

[wthif]

I wouldn't use the 82 heads just because they use a corse thread injector. Which sometimes are harder to find. Also from what I understand the corse thread injectors will only flow so much fuel. The pop pressure can be changed though. Your choice just depends on what you want out of it. As to the high nickel content I don't know. I do know the heads on my 82 engine sitting in my garage all have small cracks between the valves but that didn't seem to cause in problems.

On Edit : The 82 heads also have a coolant passage that tend to leak if not properly blocked. GM stopped making the kit. So you'll have to make something custom if you do.

[ 04-06-2004, 06:12 PM: Message edited by: wthif ]