I have a 1976 F-150, with a 360(big block) in it. I just ordered the K&N extreme flow lid, and i already have a K&N on it. Id like my motor to flow the best i can get it to. I was thinking to go with duel 3" pipes, Flowmaster mufflers(2 Chamber), and dump it out in front of my rear tires. I didnt know if im going to lil extreme with the pipe size, and maybe go to 2 1/2" instead. Ive heard both go with the 3, and 2 1/2. So please tell me what ya think, Thanx

 

"FE" block. 3"=too big. Use a pipe sizing chart; here's one.
www.dynomax.com/techsupport.stm#TechTips

 

Yeah, stay away from the 3". A big-block is a torque monster. You don't want to give any of that up.