heres the motor machined vortc heads for .550 lift 350 .040 over flattops 9.35 compression air gap 750 vac.sec. headers&duals 308 gear TH350 72 chevelle.from what i read the vortecs could use more on the exhaust side. my 70 has the nitrous grind#12-556-4 this runs strong my vortecs have 202&160 valves+port&polish 342 gear&650DP and its a 383.the other cam im thinking of is a dual energy grind#12-209-2. its the womans car so its a driver.what do you think am i headed in the right direction?thanks buzz

You could post which cam that is!
I had to look it up.
It's the DE275.
Yes that should work, or the HE 268.
Or the 260 for the stock idle.
With 3.08 in a driver velle, a performer might be a better choice.

The N2O grinds are 113 LSA IIRC. A little high for a 383. But for all I know, that's the 284 grind!
I have the UD276/284 in my 383 vortec Camaro. Great low and mid. Still need to see why it drops off so much after 6k though. Did 113 mph with the G tech and spinning most of 1st the other day. I was happy. Need to get it ready for the strip to see how far off the Gtech was.

I favor the XE274 for any 350/383 daily drivable vortec combo. Very tame but makes a crapload of power... I've seen cars go 11.90-12.40's depending on weight with it. I remember some magazine dynoed a 10:1 350 with stock vortecs and the XE274 it made something like 449HP @ 6000RPM

My sons truck ran 13.50-13.51 this past weekend. Its a 355, flattops w/4 valve reliefs, vortecs, XE274H, air gap and 650DP in a 81 Chev.swb(3860 lbs. w/driver) with 4.11 gears. It impressed several at the track,had to come over and check it out.

I swould strongly consider the good old CC 268HE here..

3.08's with a 9.35 to 1 CR motor...

Jmho.. pdq67