Use big cam and big heads or procharger
 

Been trying to figure out on my bbc427 bored .60 over, would i be better to run a big cam and nice big 345cc matching heads, or go smaller cam / heads and just add procharger. I like big lope and want river poker run boat, so what would be best on gas usage also? currently have bravo x drive. Any and all ideas welcome! block is sitting waiting for decisions!

Stay conservative and add the procharger. Personally I wouldn't run 345 cc intake runners on much less than 565 unless Your planning on camming it for 4,000 to 7,500 RPM. Not a real advisiable marine engine for your application.

4.25 crank, decent heads and cam with a Procharger.

Big cam, big heads, and a procharger! :boat:

Help me ? Procharger or get bigger cam and heads?

If your short block is set up to handle some boost use a supercharger. There is no better bang for your buck. 345 heads and a big cam will not be great on a 427" engine. It will move your power band way to high and you'll need some good exhaust to avoid reversion. Any blower/SC is very tolerant of poor flowing heads and exhaust and will still make excellent power. Good luck :drink:

Procharger

Remember this is only a 21 boat! I think a built n/a 427 is more than enough to get this boat over 80 mph.

Get some good large oval heads with big valves and a Cam & Valetrain from RMbuilder. You could also stroke that engine and get some more CI.
Anyone know what the bore and stroke is on a 427?

4.25 x 3.76, 427 doesn't have much torque for a boat. Even a 4 inch crank would help. The Procharger would add power accross the RPM range.

4.31 x 3.76

4.31 x 4.31 x 3.76 x .7854 x 8 = 438.8

how to contact rmbuilder
 

Can someone tell me a website or ph# for rmbuilder?

thanks!

Fixx
 

Bob 585-654-8553,, CAM AND PROCHARGER..

What is your HP and speed goal. I would see if a 4.25" crank could be used in your block. That would give you more torqe and HP. If you call Bob he would probably know. Definatly get your cam and matching parts from him.

60 over 427 makes for real thin cylinder walls ! I used to run that combination years a go in my drag car, split lot's of cylinder walls . Not a good set up for a boat or a drag car !!!

watch the cam
 

The procharger will give you excellent torque and hp throughout the rpm range but make sure you put in a roller cam. I had years of misery burning up two 454's with only roller rockers.I dont care what Procharger says you will burn up cams,lifters and pushrods even at 4lbs boost.