I am in the process of repairing freeze damage to my '77 Mercruiser 888. I need to replace the cylinder heads and exhaust manifolds.
I was told that "all 888's used 351W heads", however, when I pulled the heads, they are definitely stamped "302". Does this mean my 888 has regular 302 heads, OR were the "special" 351w heads that were made specifically for marine 302's (smaller 7/16" head bolt holes) marked "302" to differentiate them from regular 351w heads with the 1/2" holes?
One of my parts sources is trying to sell me used GT40 heads instead....I have found that there are 2 types--GT40 and GT40P--and there are differences in the spark plug angle. Will the GT40 or GT40P heads work on my '77 888? Will the exhaust ports line up? Will spark plug angle affect the exhaust manifold mounting?
While I have it apart, I am also looking at upgrading to a 4bbl intake manifold/carb. Any advice/thoughts on this?
I was told that "all 888's used 351W heads", however, when I pulled the heads, they are definitely stamped "302". Does this mean my 888 has regular 302 heads, OR were the "special" 351w heads that were made specifically for marine 302's (smaller 7/16" head bolt holes) marked "302" to differentiate them from regular 351w heads with the 1/2" holes?
One of my parts sources is trying to sell me used GT40 heads instead....I have found that there are 2 types--GT40 and GT40P--and there are differences in the spark plug angle. Will the GT40 or GT40P heads work on my '77 888? Will the exhaust ports line up? Will spark plug angle affect the exhaust manifold mounting?
While I have it apart, I am also looking at upgrading to a 4bbl intake manifold/carb. Any advice/thoughts on this?