OOPS !
DUH ! I really oughta not go OnLine until I've had my Coffee !
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Sorry about that .
If it has the 250 CID thinwall , it's really easy to wake up , first and foremost , ditch the muffler ! with a long exhaust pipe to the rear bumper , it won't be loud atall ~ hard to believe I know but I used to haul in Bel Air sans muffler and I never got any tickets .
Anyways , there are multiple cams available but the basic 1 ton cam is the best for a street driven engine . ' race ' cams always make off idle performance crappy so beware before you wa$te $$ .
You can also use two or three single barrel carbys to unleash amazing power
-BUT- ~ these thinwall engines don't live long when run hard or revved a lot .
For the beginning , open the spark plug gaps up to .060" and experiment with the basic timing from about 10° BTDC @ idle , then stamp on the throttle in top gear @c 35 MPH , if no ping , give it one more degree idle advance and try again ~ when you hear it ping as you stamp the throttle @ 35 MPH in top gear , stop and back it off one degree and lock it down ~ these thrifty engines are very peppy stock when tuned sharply . the " Throttle Ping Test " was part of GM Dealer / Factory training back when I was young and it really works .
Try the basic tuning bits I describe before going to Tom Langdon etc. for multi-carby intakes and headers , most exhaust headers are worthless in L6 engines and make them run worse until past 4,000 RPM's anyway .
Apparently , InLiner Tuning is a lost art but it's simple : just experiment as each engine combination needs things a little bit different .
Keep us posted .