5A Heads on 88 307

[rick 51]

New to Olds engines so any help will be greatly appreciated. Will they fit, does anything need to changed ?

 

[olsguy]

from what i remember the 5A heads should swap straight across but i think the intakes for the 6A and 7A heads had smaller runners to match the smaller ports on the head so you might want to look at that, and let me know because im not sure. i would also recomend getting the exhaust manifold or a set of headers for your 5A head to help swap.

 

[joe_padavano]

from what i remember the 5A heads should swap straight across but i think the intakes for the 6A and 7A heads had smaller runners to match the smaller ports on the head so you might want to look at that, and let me know because im not sure. i would also recomend getting the exhaust manifold or a set of headers for your 5A head to help swap.

X2. The heads bolt on, but to take advantage of the better ports, you'll want an A4 (or aftermarket) intake and the earlier cast iron (as opposed to tubular) exhaust manifolds.

 

[rick 51]

Thanks for the prompt replies, going to tap your brains again. Any ideas on where to get a pair? :?

 

[olsguy]

i see alot of 307s in the junk yard aroundmy town (im from omaha NE). they came in almost every GM car from 1980 to 1990 i think. the 5A heads were used up to 84 and and i have seen some on a few 1985 cars as well. but just find a car at the yard that has a 307 and scrape the crud off the side to find the casting mark ( it shoud be at the front drivers side of the engine) or you could call local machine shops to see what they have.