I have two camel hump heads that I'd like to use since it's all I can find at the moment. One is a 3927186 and the other is a 399149,(maybe this one is a 399492?) Anyway, it seems they are not the same as far as port configuration is concerned. They have been ported, with 2.02's and 1.6's, and otherwise prepped identicaly. Will this cause a problem in how the engine will run? I'm sure they won't flow the same, but will this really make the engine run bad?

Larry

 

The heads arent going to work properly if mismached. You can use different casting numbers as long as the runners, combustion chambers and valves are the same size. Well, at least having two different heads is better than 1. If I were you I would take the numbers and hit the junk yards and machine shops up for a match or compatable casting.
Good Luck!
SSC

 

you can still buy them new from chevy (the 426 or 486 castings i believe) their the camel hump fulies with 1.94 valves. not sure if that will help but they might be able to match them up for you. their like $450 assembled a set. if you have trouble with a dealer, ask any pro stock racer, thats the head most of them have to run. my buddy bought 3 sets brand spankin new from chevy this (last) season.

 

Well, depends what you're looking for..case in point..

We used to have a'54 Ford 2.5 ton truck that we hauled our D4 Cat (usually with a dozer blade on it) to the jobsites.

Engine was a 292 V8, IIRC, but when the engine finally let loose and we tore it apart, it had two different heads on it, one from a 312, the other a 292. valve sizes and combustion chambers were obviously different to look at.

Would have never known by how the engine ran though.