what kind of gains?
 

i have slp loudmouth and i just ordered mac true-fit long tubes with off road y-pipe and no cats. what kind of rw gains should i achieve with this setup?

you mean mac mid lengths ;). figure ~20rwhp, little more with tune.

haha...yeah my bad. ok thanks for the info. how much could i get out of a good ls1 edit and this exhaust?

Get a tune and port the primaries on the Macs, ~30 rwhp with a good tune

i dont know if its as bad with macs, but i really wouldnt keep the loudmouth without cats. with my lt's and ory it sounds TERRIBLE. just fair warning to ya

i second this, i made the mistake of a loudmouth without cats. i think a bullet muffler to put in place of the resonator would be around 40 bucks or so, and another what 50 to install tops? i would suggest that set up

30 rwhp...ehhh with a good tune yeah its acheivable. but every car is different so to be safe ill say 20-30 rwhp with tuning.

ok...so i have one more question. can anybody lead me to a place where i can read a "how-to" on installing these headers and y-pipe??? please let me know cuz i wanna get ew on asap. thanks

I think there is a sticky in the new LS1 enthusiasts section that has a bunch of sites with how-to information... Good luck with the installation... :cheers: 20-30RWHP sounds like a good estimate...