^they make them in 6" also
http://www.speedwaymotors.com/Speedw...Rods,1790.html
As for everything else i like 6" rods myself but its all up to you..you know your crank,figure out what comp height you want on your pistons an then where you want them for how far you want them in the deck and then figure out what rod fits..me i like pistons with 1.18-1.26 comp height..they can take a load of spray no problem..an it puts the pin not in the oil ring and not way down either an still have plenty of meat up top..but to each there own.
Are you stick if your auto your already around 425hp at the fly wheel an if stick your around 390..remember these trans,rears and drive shafts aint like racing shit..your losing more then you think i've always gone with 100-150 for loss wise on stock cars
What is your weight? stall? gear? shock set up? all that..remember the lt1 bolt on record is held by tom and he only put down 309 rwhp and was 3100 for weight on his 11.48 pass.Yes he was creative and used alot of super stock tricks like engine oil in the rear gear,light brakes an made sure they didnt drag at all an so on.