Hi everyone, Im trying to find some info on the heads on my truck. I bought the truck used and the guy said it had a new engine in it.. Come to find out by running the serial that the engine block shows its a 305 cu in, 'H' vin LG4 engine, 150Hp w/ 4BBl. The heads on the truck are 14101081. Im trying to find out what size valves and what size combustion chambers. I have another set of heads that are 3986336X heads but I think they are 76cc chambers and I dont want to put them on and kill my compression. I looked in the stickies and it made reference to 081 heads but didnt tell me what Im looking for. All I can find about them on Mortec, etc is that they are 87-95 305 heads.

Anyone with some info on these..

The engine runs great and doesnt smoke or anything so if I dont have to change them I wont. I will put in a new cam, intake and some headers and go from there.

Thanks
Shane..

 

They're half decent factory 305 heads. I believe the same heads were used on 305 TPI motors from 87-up as well. ~58cc chambers, 1.84/1.50 valves. Being 87-up heads they share the somewhat oddball 87-up intake bolt pattern (no kidding, right?).

Not a ton of carb intake choices for 87-up bolt pattern heads (some entry-level performance intakes from Edelbrock and Weiand are available). You can use an intake for a "standard" 86-down intake bolt pattern with some minor modifications to the two center bolt holes on either side, however.

 

Well I will keep them then since they have the small combustion chambers.. How hard is the mod to make an older intake fit? I have a brand new Edelbrock RPM intake that I would like to use. I will put a new cam in and some headers and hopefully have some power. I am also gonna check into burning my own chips if it isnt too dificult..