I am building a mild 509ci BBC. I'd like to get 500-525 HP. The bottom end, basically a 502/415 GENVI motor bored .030. Plan on using a 525 camshaft. What heads would you use? Manufacturer, cc, etc., etc.

Hate to say it but yes cost is a factor But I'm willing to spend extra $$ for quality.

Will be put in a 1999 '25ft. Active Thunder Tantrum

The peanut port cast head is the head for you. It will make outstanding torque from 2000rpm right up through 3500rpm, right where you need it. The only other option might be AFRs, I've heard tale of folks doing well with those too.

BT

Not much top end, though. I'm deliberating the same question -
-I have 4 peanuts and 4 rectangles and 2 x 468ci in a 28' Checkmate.
-I have two Wieand open plenum and two original dual plane HP aluminum intake manifolds.
-I have two Q-Jets and two 1050 Dominators.

I plan to use the rectangles, the original HP aluminum intakes, and the Q-Jets for economy running and will swap out to Wieand and dominators for high speed running. While I know the head runners are oversize for a 468 until about 3500 rpm, I'm buliding to 6500 WOT. We'll see how much of a dog she is coming out of the hole and I may reverse the rect port decision...but that's my plan for now.

Sshh, don't tell raddiction that, I can't have him rompin past me laughing his ars off

My setup is similar to yours NW but my cid is 470. Rect port heads, dart sp intakes last year with 800dp. Runs pretty strong and I have been happy with them. Couple years back I ran same edelbrock alum rect port heads with dp performer intakes. She ran better then. I actually lost 2mph going with the single plane. Now I am going with small blowers and dominator carbs. If I go back to n/a it would be with the dp peformer intakes. I have 2 blue hp 500 takeoff carbs to sell (800dp) if you are interested. I would definately dump the qjets and I have spent a lot time an money trying to make they work, they just can't match the holley.

Based on your rpm goal, single plane is a no brainer and I think the dominators a good starting point.

BT

Afr 315 cnc but get a custom cam. The 525 cam is actually a little big for that combination. 550 hp with excellent drivability will be easy with that. Dammit Donna was logged on, Ian

If you are saving money and only want 525 HP I would use the Dart Iron Eagles 308 cc 1600.00- 1700.00 complete with inconel valves.

Aren't the Edelbrock marine heads about that same price? They seem like a deal for an assembled aluminum head with inconel valves- what's the catch?

AFR 315cc CNC Ported,Hard Anodized water jackets, Inconl upgrade, that should do it. PM me for a price.

The Edelbrock marine heads don't have springs, retainers, etc. They still seem like a pretty good deal. How much are you leaving on the table for a nild 500" motor compareed to AFR's

Stay with a large oval port. No need to go more than a 290cc, but don't go less than around 270.
GM and Edelbrock make a 290, Dart makes some great pieces too.
A 100cc or so, combustion chamber would give you around 9.5:1 with a flat top as long as you were alittle less than .020 in the hole.

my .02
DAVE