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-   -   502 upgrade, anyone got a good setup? (https://www.offshoreonly.com/forums/general-q/241384-502-upgrade-anyone-got-good-setup.html)

hotjava66 10-25-2010 10:34 AM

502 upgrade, anyone got a good setup?
 
Thinking about upgrading my 502's 425hp carbed, gm performance based, holly marine carbs (800) and stainless marine exhaust. Im thinking right now I want to get around 575hp, change heads/cam/intake, and want to run on 87 octane. Anyone got a good similar setup they have already done or reccomend a good head/cam/intake combination

Kidnova 10-25-2010 05:01 PM

easy..... call rmbuilder 585-654-8583

1BIGJIM 10-25-2010 08:52 PM


Originally Posted by Kidnova (Post 3238269)
easy..... call rmbuilder 585-654-8583

Bob Mandra:drink:

MILD THUNDER 10-25-2010 09:03 PM

Use your heads, Crane 741 roller cam, Roller rockers, dart single plane intake, holley 800 carb. Probably be right at your goal, or close to it!

Ghostrider 10-25-2010 11:29 PM

Will the 800CFM be enough for 502's running the 741?
I'm running an 850 and building a similar setup.

Are you running the TBIV ignition?

Griff 10-26-2010 03:07 AM


Originally Posted by Ghostrider (Post 3238600)
Will the 800CFM be enough for 502's running the 741?
I'm running an 850 and building a similar setup.

Are you running the TBIV ignition?

Plenty of carb for them.

Thunderstruck 10-26-2010 07:33 AM

I sent you a pm. Call me.

Shagnaz 10-26-2010 08:41 AM

I don't know if you're running a blower, but could you put a set of rectangle port closed chamber heads from a 69-71 BBC to bump up the compression to gain some more power?

HaxbySpeed 10-26-2010 09:35 AM

1 Attachment(s)
AFR 265 oval heads, Vic Junior intake, RM Builder cam and valvetrain. Easy 600+hp. An 800cfm carb is just barely big enough for this app and would need a bit of tweaking to optimize. A 950ish works better. I did a pair in a 29 Baja upgraded from 502Mag MPI. It went from 68 before to 86mph after! They made 630hp 605torque. Bob's the man!

MILD THUNDER 10-26-2010 10:01 AM

You should have the square port heads i believe. Of course their are better choices for heads out there, but if your on a budget yours can work to meet your goal. I highly recommend sending your heads to Jimmy Valayko in grand rapids for a little magic, bob madeira cam, and you'll be a happy guy. Adding a solid 100-125HP per side in your 28 should make you grin.


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