Power tips

[Leedo Lanes]

Any you guys got any performance tips for me and my 4.3 liter without pulling it and putting in a 350?? This is for an 89 Sportfire I/O

[Leedo Lanes]

Any you guys got any performance tips for me and my 4.3 liter without pulling it and putting in a 350?? This is for an 89 Sportfire I/O

[jrumon]

Leedo... all he same type perf. stuff you would do to a 350 applies to that 4.3 of yours...

Better exhaust (Kodiak aluminum manifolds), edlebrock aluminum intake & Holley carb, Comp cam (magnum marine series), Crane roller rockers, 6M MSD marine ignition, ported the heads and had bigger valves put in (MARINE EXHAUST VALVES!!!), mill the heads a bit to up the compression, etc.

I built a 4.3 for a friends Sportfire... motor went up in power substantially... modified motor ran 5,500 RPM with a 23p mirage prop (2:1 lower unit ratio)...stock would only pull 4700 with a 21p! All mods (about $2000 total) were bolt-ons to a stock shortblock!!!

The ONLY thing I didn't like was the SOUND of the V6 exhaust with the straight thru-hull... he has since put a Corsa "balance tube" in and sounds much better (still not that V8 rumble but runs like one)!!! It's worth doing... Jim.

P.S. This could probable all be done with the motor in the boat if you have room to get the cam out... (We did it on a stand while he was detailing the motor compartment).

[Leedo Lanes]

Hey Jim,

Thanks for the advice. This is great. Just what I was looking for, someone who did it already and had some experience with how it went together/ran. I wouldn't want to spend a lot of dough and be unhappy with the results. Thanks so much for the recomendations...