88Spyder

A bit new to the performance end of boating,been drag racing BB Chevys for awhile
Questions about cylinder heads,I am in the process of redoing the 454 in the boat,will be at the machine shop shortly,Its a 26 foor spyder,single BB, I have a chance to get a set of aluminum oval port heads with 2.25 intake and 1.88 exhaust valves.At this point would I be better off just going to a stock square port head and having a performance valve job done on them,the 454 will be 60 over,steel crank,steel H beam rods and a compression ratio of about 9.75 to 10.0
Any help would be great

BenPerfected

Don't know about the aluminum heads you are considering, but the 80's generation GM small oval port heads on the 330 HP or the sq port heads on the 365 - 420 HP were all about maxed out by Mercury. With the stock heads, you can spend a lot of $ and not end up with more than + 30-50 HP. With the right cam and heads, 500 HP is reasonably attainable.

BY U BOY

i went with the large oval aluminum heads 2.25 and 1.88 with 110 cc chamber really woke the engine up. I was also running the zz502 cam and intake with 10.7:1 compression.

88Spyder

Just got the cylinder heads off and he cating number is 3933148, hese look like small oval ports o me,like I had aid before I'm use to big inch drag motors turning high R.P.M. using square port heads to get the breathing done,are these worth doing anything to,usually cheaper to buy asembled heads then to start puting in bigger valves and porting work? they have the 2.06 intake valves in them.

Also any suggestions for a machine shop that specializes in Marine applications in and around Ct.