Originally Posted by Däs Schmoo

Shorter gears will always accelerate better than longer gears, boosted or not. The only reason I would see to use longer gears would be to avoid shifting into 5th if you were trapping speeds that exceeded 4th gear redline.

LS blocks are dirt cheap, so if you don't feel comfortable rebuilding your current one, boost it until it blows and just replace it with another one.