What about this that Nineball replied to an earlier thread I had posted:
Don't do dual cutouts for a 346ci setup. On my old heads/cam setup I tried that (dual 2.5" cutouts where cats normally would be on an offroad Y-pipe) and I lost a TON of torque. Only gained about 2 rwhp peak vs a single 3" midpipe cutout. Ran slower at the track too |
Needless to say, that setup was ditched after a week. Went back to the single setup and got my ET/MPH back.
One of the biggest LS1 mistakes I've made to date
I really don't want to cut up my Jet Hot coated y-pipe unless I'm really sure its gonna work or help me.