THANX FOR THE INFO
COOL SITE...

I had bought 365 Mag rectangle port heads all 365 hp have rect heads. This was off a 1991 boat. Heads, block oil pan Steel crank.

1. Sent heads out for valve job, did not replace valves,had them dipped new seals cleaned up, heads decked .030

2.Crane Cam 286/296 .05 112 Flat Tapped matched springs
Gold Series Roller Rockers

3. Bought 500 hp valve covers grind the tips out, Its a must

4.Elderbrock RPM Air Gap.

5.850 Holley

Dynoed 470 flbs@ 3500 420hp @5000
This set-up brought on 400 flbs at 2500 and 439flbs @5000
and didnt miss a beat.

I tried many different carbs and a Victor Jr intake but the Air Gap was the best set-up with the 850

Hope this information helps

I got alot of parts from Jegs and Summit. I also used alot of parts from my totally wasted 330.

When it was all said and done I spent $5,200 that included the Dyno testing, the take out and put back and Misc.

Everyone says they could have done it for a whole lot less!!!!!

This was my first motor.

Good Luck with everthing.

Nobudget

Sweet. Thanx for the info!
You are the 3rd person today to bring up the RPM intake as a good choice. Think I'll make it mine too

I know this isn't a test, by why I'm at the well-o-experience :

- Any guesses as to what the 0.030 deck bought you in terms of static compression ratio?
- Any idea how far you can go, deck wise, before hitting the never- popular but always-present "practical considerations"?.

Not sure what the increase in .030 decking would be, but I am about to test an assumption on rect port heads vs oval port. I had fancy rect port al edelbrock heads on my 365hp mags. Nothing but trouble... and nearly out run by a single 330hp baha 240. I am in the process of changing to oval port cast iron heads with edelbrock performer intakes. OSO generally says rect ports can't support the low rpm (5k) of boats and that oval are better. I am going to find out. The rect ports don't start working until 6.5k rpm and I will never be there with my boat. I am thinking oval ports are the chit with a boat and gonna find out. I"ll let you know what happens. 330s come with ovals.

BT

Just a point of clarity. 330's come with peanut port oval heads (truck heads) that make good low end torque but run out of capacity over .500 lift (except for the late model vortec heads). The good oval ports are the early Gm heads (cast number 049 or 781) that have large oval ports. They will do better than the rectangular ports in the 5000 rpm and less range with large valves( 1.88 and 2.19). However, Jim V has made some good numbers massaging the peanut port heads. I run torker 2 intakes due to deck clearance problems. I agree the airgaps are better if you have the room.
Tom

Milling the heads .030 will increase static compression from the stock 8.75 to real close to 9.0 and .030 is about as far as you can go on the heads before having to modify the intake according to my machine shop.

i have a pair of large oval port heads sitting in my garage
They came off my 1987 454 "mag" basicallya bone stock 330 7.4. unless the large oval port heads were what made them a "mag" didn; seem to make any HP difference though...

Formula31 is correct. Go to the large ovals with the 2.19 intakes and 1.88 exhausts. I did make 422 HP last year with peanut port heads, but they had the large valves in them. Low end and midrange was great, but it would run out or steam around 4800 RPM. I went to the large ovals this year, but I am not in the water yet. Also, don't worry about the cast crank. It's good to about 500 HP. Have it line bored, make sure everything is straight and it will be fine.