A compression check lead me to a cracked head on my 1989 330hp bone stock Merc 454.

A buddy (who I trust) has a set of stock 049's (2.06/1.72" valves, no porting) that just need freshened up. If I put them on along with a Performer RPM Air-Gap intake what power increase can I expect?

He's selling me the heads for $150 vs $125 for a replacement 360 peanut port head so I can't go wrong there. The only really extra out of pocket would be the AirGap ($236 in Summit).

Thoughts, suggestions, advice? I really don't want to make any big changes as I plan to do an new from the ground up engine next winter.

It should make a small difference. A mph or two. They will be good parts to have with your next engine also. To really wake it up, you'll need to change the cam and carb too. I reccomend the Merc 420hp cam if you're on a budget or the 731 hyd. roller if not. Both are Crane. And a Holley 800 dp.

i was gonna add that too, might as well do the cam and carb as long as your there!! itll gain ya a little bit, might make ya happy to a season or two!!

For that money, go for it. They really need the bigger valves and some poring and bowl work to get them going. Youre paying basically for the castings and the rest is gravy. Use them for now and do them right for the next engine or buy new.

I have a smoking deal on a set of heads ALREADY to bolt on...If your gonna do it...Go big or go home!...You can bid or PM me.

Dave

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMESE%3AIT

Cept they wont fit on his mark 4.

and I don't think rectangular port heads (088s) would be worth a darn on an 8:1 cast piston shortblock. If I had higher compression and forged pistions, I'd seriously consider it.

Next question, how big of a cam can I put in and not change my pushrods and rockers?

i have a crane 741 hyd roller cam i'll sell cheap it have 150 hours on it

What's the full p/n on that so I can look up the specs?

Too Big for basically stock 330hp, especially with stock exhaust.

Go with a cam just slightly bigger than a stock 454mag cam. Something in the range of a crane #133802.