Re: General Performance Enhancements for Marinized Ford 302?
The Edelbrock Performer 289 is an aluminum, 4-bbl intake, that is just a touch better flowing than a stock cast manifold. More importantly, it will have the flanges to accept your 4 bbl carb correctly.
If you want a little more grunt there are better intakes, but many of them are made to flow higher rpms. Performer gets it's power from off idle to approx 4500 rpms. Typically, if you move up in performance on an intake, it will generally work better with a better cam and heads, but typically this moves your power up to a 2500-6500 rpm range, which is fine for cars where we do this rarely, but not for a boat where you will like to be around 5000-5400 rpms for long periods of time, and your torque migrates up the rpm range as well, so you will lose your out-of-the-hole lower rpm torque.
GT40 heads are a REALLY good upgrade for small block fords (STAY AWAY from GT-40P heads, you cannot access the spark plugs on those without special headers or exhaust manifolds). They flow superbly, for a cast iron head, and yet you can still snag a set for $200-$400 a pair.
For a couple hundred bucks, you can upgrade your cam to a roller cam, and still keep it mild, then put in roller rockers and lifters, and free up some low rpm horsepower and torque (easier to do with a 5.0 block, as parts are readily available). But you can use the GT40 heads with a flat-tappet cam if you replace the springs with ones that are rated for a flat tappet.
My current 5.0 is a bored over .040 5.0 non-roller block, retrofitted with roller cam, roller lifters, full roller 1.7 rockers pumping around 360 hp and torque starting around 3000 rpms and holding that torque curve up through 6500 rpms. I regularly spin it to 6500 and sometimes 7000 rpms for short durations (drag strip, showing off for friends, etc) but it has plenty power and actually keeps decent gas mileage through 4500 rpms. It will run 5500 rpms all day long without any stress whatsoever, pumping out a good 350 hp and 350 torque.
I built the entire engine (for a car) with used parts for about $400, with the only new part being a Holley double pump carb for another $600.
Specs of the engine are located at my website, if you want to check out exactly what I used and see dyno run (chassis dyno, not at the flywheel numbers).
http://scooper77515.fordmaverick.net/index.htm click on Spec Sheet for the engine part numbers etc.
