All: My machine shop has just informed me 1 of my '70 350 heads is cracked. It will cost over 100.00 to fix. I will be using the '70 block, but now need to replace the heads. Since the engine will be going in the '73, can I use '73 heads on a '70 block? Can '73 350 heads be modified to perform at similar pre-smog performance head levels? I realize the combustion chambers are larger on the '73s but can milling the head surface make up for the added volume? Will this cause valve train interference? Your advice is appreciated! :TU:
supposedly all buick heads are very similiar in combustion chamber size. Compression difference is from the pistons.
combustion chamber volume will only be a few cc's bigger on those heads. i THINK they are a straight swap, too, but i am not sure. later heads will have EGR holes and extra water jackets that will need to be plugged, but i am not sure in what year either feature was put into use. thinking at least 74 or 75.
I believe after 72 they added a coolant passage. It's in the middle of the head where the block and heads meet. Be careful? Frank
70 heads i had a set of 75 heads i was going to put on 70 350 but coolant passage in the center of heads to cool crossover wouldnt work on my block so i rebuilt the 70 heads but i believe there is no other difference.where is the crack at as another guy i know cracked his 77 heads and they found a shop to fix them not sure how good as heads only have 50 miles on them andy
See if they can find you one with the same casting #'s. I just went through the same thing but mine had a hole.
