Okay i am sure i have a 302 block (after checking the ford engine data on here) what i am not sure of is the heads. The heads have 351 stamped on them. This is a motor out a mid 70's ski boat. Mercruiser 188 hp. That i believe has been rebuilt at least once. Any help?

 

What's the casting number on them?

 

Welcome to FTE.

IIRC, the casting numbers for those heads are under the valve covers like so:

http://diyford.com/wp-content/uploads/2013/11/1130.jpg

351W heads on a 302 or even 289 was a performance trick in the '70s. It gave you bigger valves and ports at the expense of a little compression due to the larger combustion chambers.

 

Actually, (and I might be incorrect to a degree) Ford Marine engines usually had the 351W firing order, which means a 351W cam.

I believe they also used 351W heads.

Not a "mutt" - just the way it came from Ford Marine.

 

Makes sense. I recall an RV with a 302 that had the 351W firing order, not sure about the heads. Mix and match is a good thing. Isn't it?

 

Might have been a 302HO.

In the case of the 302 HO, same thing, I think. 351W firing order, roller cam, and maybe even 351W heads. I didn't get involved in the 302HO much back in the day, so I can't be sure.