Originally Posted by Coolrider
I know! My mecanic friend says the same good things about the 700r4 so... I wanted to keep my fact. powerglide but... It seems that i won't have choice to set with that transmission i think. He's a transmission specialist with great knowledge in race track setup and wants to build one for me.
The PG is not good for acceleration in a heavier car, but the top speed is not affected one way or the other- it has a 1:1 ratio in Drive, same as a TH350/TH400, etc. So the top end speed is going to be the same, or maybe a little higher due to less frictional losses.
Where you can have the better of both worlds is to use a TH2004R or TH700R4 like mentioned already. They need help if stock to hold up well to a performance engine, but it can be easily done- for a price. Even a properly built TH350 or TH400 would be better for acceleration than the PG.
The thing is, you can cam yourself out of being able to use OD unless the rear gear ratio is very low- like 4.56 to 4.88. A 4.88 rear gear would give you a 3.42:1 ratio in OD. A 4.56 gear = 3.19, and that is about as low as you can go w/a relatively big cam w/o bringing the engine rpm down so far that OD becomes useless.