soldsoul4foos

Need to freshen the top end of my 454 Mag. Something has happened to a valve, and a friend of mine and myself (mostly him with the mechanic skillz) are going to go with new heads, cam, rockers, exhaust headers, intake, and carb. Does anyone have a setup that has been tried and tested that will work with some added HP while also keeping the boat a daily driven lakeboat?

Thanks,
Bill w.

Pat McPherson

What is your budget?
How much HP you want to make?
You may consider the Edelbrock large oval marine aluminum heads.
Have RMBuilder select the cam for you once you have picked the heads.

AIR TIME

I have a 509 with merlin 310 heads, 9.5 to 1, S/S dry pipes, 1050 dom, isky cam about 622 617 244, 254, 114 I think on the cam I'LL HAVE TO LOOK IT UP. DART INTAKE. HP ON THE DYNO was with a 850bg carb ,5100rpms 600hp at 6000 rpms 647, tq was 637 at 4800. now with the dom 1050 nickerson add 20hp the bad part is the boat ran 83gps at 6000 ran out of prop. also added a 2'' shortie. builder was jim reid in whitman mass. with stock heads crane cam made 585hp 580tq, art

MILD THUNDER

iTrader: (3)

I would have the stock heads redone, install a hotter cam with about 228/236 duration, some roller rockers, edelbrock air gap intake, holley 800 mech secondary carb, and a good set of performance manifolds. Should get about an extra 75HP out of it.

Figure on about 1k bucks to do the heads with new valves, etc, (inconel exhaust valves), Rockers 250, cam and lifters 200, carb 500, intake 250, exhaust 1500. Should be around 3g after all parts and gaskets, timing chain, etc. This is considering the shortblock is ok.

Payton

You can make real good power with the Mag heads,if you have the right guy work on them.
http://hometown.aol.com/valakoracehe...raceheads.html
I went with Crane 241 cam, Gold rockers Weiand single plane intake and 800 Holley. I make about 425hp. I would be at least 450 of I had let JimV work on my heads.

$$ wise, I was under $1000 per engine. I bought the carbs used. It would be Another $700 to upgrade to roller lifters and $1200-1500 for the headwork.

MILD THUNDER

iTrader: (3)

How much speed did you gain when you upgraded the mags payton? What does that SW top out at now?

soldsoul4foos

I JUST picked up a set of 990 casting # gm heads from ebay this evening!

RJBBC

We had Tyler Crockett install his upgrade kit on our boat. The kit included milling the heads, new valves, rocker arms, push rods, cam, exhaust, etc. Our 454MAG was dynoed at 461HP (5100RPM) and 514LBS (3700RPM) after the installation. The 25ft V went from 65mph GPS stock to 72mph GPS with the kit and a labbed finished prop. He will sell you the parts to the kit if you would prefer to install them yourself. We have put 36 hours on the engine since the upgrade and it runs great.