You obviously know what the new parts will cost, and have that much to spend. So, talk to the guys at KRE. They can build you a set of their 65cc D-ports, with smaller intake valves. No need for the 2.11 valves. There is a road racer on the PY site who had a set built, with 2.08 valves, if I remember correctly.. Probably 2.02's would be big enuff. That's bigger than the stock 1.96 intakes. (I believe the '69 350HO, with #48 heads, was the only early 350 to use 2.11 valves.) As mentioned, the Kaufman's can fix you up with the heads you need.
Then, with having more compression, you won't need a Voodoo cam. You can go to something like a Summit 2801. This cam is basically a higher lift version of the Pontiac 068 cam.
Assuming your shortblock is in good enuff shape to survive with more compression, the combo of more compression and cam, should add quite a bit of spunk to your 350. The alum heads will also take some weight off your front end. Add a Performer intake and alum water pump, and you'll be even lighter. With a properly tuned Q-jet, you should have decent power and gas mileage--a nice little street package.
Using the old iron heads will require new stainless valves, a GOOD valve job, screw-in rocker arm studs and hardened valve seat inserts. Then, if you have any porting at all done, you'll have well over $1000 invested. And, you'll still have the heavy iron heads. If you run 'em at 72-75cc you'll still have fairly low compression, and will need a small Voodoo cam, like a 256, to increase cylinder pressure. Of course, as always, this is just one opinion--and opinions differ.
Example: 350 + .030 overbore, 75cc heads, 5cc valve reliefs, .027 x 3.95 Cometic head gaskets, .020 deck height ( a guess)
Put these numbers into the CR calculator and the static compression ratio is 9.24, which should be safe with pump gas, with a regular cam, like the Summit 2801.
BUT, if you still have a standard bore and run the cheap Fel-Pro head gaskets that most use, the CR is only 8.78. The Summit cam calls for at least 9:1 CR. So, the Voodoo might be good in this situation. Now, I've read of several guys who have actually measured those old 350 heads, like 17, 47, 11, and found that MOST of them have bigger than advertised chambers. Those advertised at 72-75cc measured closer to 80cc. That would reduce the CR to 8.38. So, if you use iron heads, you'll need to have 'em measured and cut down, IF you want more compression. At 80cc, you will definitely need the Voodoo cam. IMO
Note: All these CR numbers are aprox. I had to guess at some of the numbers, to plug into the calculator.
