Triniemi, Lots of Heads for a 509 would be good. I have built numerous bracket style 509's that make 850ish hp with Pro-1 325's that I have ported. I will jump on the Victor band wagon, you could even use a mildly done up 340cc version from Edelbrock. No need for custom cnc work. With a revised valve job, and some detail work, those heads will make 900+hp without being crazy on cam, compression etc. Maybe not on a 509, but, that 850 number would be easy enough. I think 850hp in that chassis, would scream. The newer Platinumn version of that 325 head, is pretty good. With moderate work, and a good valve job, 400+ cfm in a usable lift range is easy enough. I had one pump gas 496 make 780 hp with a set done up, with not all that wild a cam, and that was a 2.25 intake valve. They have potential, and, Curtis isn;t the only guy out there that can make power.
There are other heads out there that make power. Last year, on a tired short block, I did a set of Canfield 350's, with what I consider a bracket race cam, the engine was for a Super Street Chevelle, 10.90 index, and a bracket car. 580 cubic inch, under .800 lift, 14:1, a 1050 carb, that was totaly choking the engine, used primarily for response with the throttle stop, The Canfield 350 heads I ported, did a good valve job, with 2.325 intake valves, they moved 438cfm at .800, 441 at .900, and it was still a 45 degree seat, The port volume, ended up at about 375cc, after the ports were sized correctly for the application. The engine made 950hp and 785 ft/lbs. This was not set on kill, spun less than 7400 rpm, and was brutal.
The engine dominated a local heads up naturaly aspirated "real Street" type class. In complete street trim, dot tires, exhaust, 3600_ pounds, power glide, 4.10 gears, using a msd digital 7 to kill power out of the hole, to hook it, it still went low 9.40's high 9.30's at 144+, in 90+ degree heat. Make it 622 inches, and give me a real cam, and that thing would make some real steam. Those heads are actualy in Sweden now, going on a Pro-Charged engine and should run real well.
So, to answer your question, there are numerous heads that would work. Probably the best bang for the buck, would be mildly done Pro-1's, or the Edelbrock Victor 340cc, with some detail work.
Frank
Advanced Performance
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