Let me get out my soap box.

Get rid of that 3.08, it is good for nothing behind a six, you will spend too much time on the power stage of ANY carb trying to go up any incline or pull any load (even a bed full of ping pong balls).

The PowerGlide only suffers from a too tall low gear ( its a rugged tranny, rugged with beefier planataries than the Torque flites), and with out a lockup torque converter its no different than a turbohydreamatic in the final 1:00 to 1:00 drive ratio. Now a turbo 350- will scat fron the light better due to the difference of a 1.82 vs. a 2.56 low range ratio, the 4-speed autos really shine with their 3.06 or 3.08 lows, but with a 3.08 rear gear you are doomed in the o/d position.

It will take a 400+ engine to be "happy" with a 3.oh my aching back 8 rear gear.

I would try removing out one of the stock dist. centrifical weight springs and run only run one of the weakest springs you can find (keeping an ear open for pinging) to try to put a little snap back in the buggy-- I'm afraid the 3.08 wont let to go that far. But you can alway start back by getting a little heavier spring and maybe go back a pair of weak ones--Set the static timing at 10 degrees at idle with the vacumm can connected to MANIFOLD VACUMM anywhere below the throttle butterfly. This hot timing setup may force you to burn a better grade of gas, but it sure will feel better. Its nearly free cost wise (springs- not rear gear change-but not all the Chevy twices suffered with the Salisbury design rear ends), and the results may pleasantly surprise you.

As long as your high milage motors are firing on all holes your milage will not suffer as greatly as some may lead you to believe- I fell that your milage will begin really to go south when you start running on less than all cylinders rather than six weak ones. Perhaps with six crippled cylinders you may see a max of 10 to 15% reduction in mpg. But MPG is one of the most incorrectly and inaccurately measured factors seen. Most of the errors are thinking the amount of gasoline placed in the tank is actuaaly the amount consumed at that filling. If you trust that thinking, them the challange is to run another tank through it an compute that--and then keep a running total going - the more tankfuls, the less quanity of fuel errors. We all have had the neighbor with the (one tank check) 24 mpg lincoln with the 462 motor! And keep a close eye out fot those pumping losses.;

Last edited by edski; 05/09/11 07:19 PM.