It's all up to the amount of room you have. That's the main factor
My car being stock with T bars and stuff it's all a trade off. I just went big and unequal lengths. 2&1/4 with short and longs lol. It's hard get the fronts short with stock shocktowers.
These were what put my car in the fives in the 1/8. I had hooker fenderwell supercomps and it would run hi O's. Only thing changed were headers and it went low .90's