I hope the overdrive solves that problem.
I'm not sure why you're taching 4000 at 80 MPH. Thunder has a 4.1 rear gear and 28" diameter rear tires. Arizona has a 75 MPH speed limit on the freeway, which means that I will cruise at 78 MPH. That's 4000 RPM on my tach. Thunder will cruise that way all day and twice on Sunday and never cares.
Your stock engine shouldn't have cared, either, unless old age and wear had simply set in.
What is the best way to do that?
I just E-mailed that to you, privately. Read it all.
They said 600 HP would not be a problem.
For 30+K, it's not a problem in a 350, but the engine will never idle on the street, unless they put in a 200HP nitrous shooter. For nitrous, there's some serious piston, rod, and crank work that needs to be done, unless you don't want the engine to survive more than about 50 nitrous shots.
400-450 HP is more realistic for a 350 on the street running on a carb. Milton Schick 1964 442 Cutlass [EMAIL PROTECTED]

