One of our customers, Greg Jackson, installed a Pypes 2.5" X-pipe system & Pypes StreetPro mufflers on his 1971 Pontiac GT-37 in his driveway on Christmas day 2011. This is what he had to say about the install:
Here are some pictures of the Pypes Street Pro exhaust system with "X" pipe that my son and I installed on our old 1971 Pontiac GT-37 that we bought from a junk yard in North Carolina in 2009. The car had been off the road since 1995 and the engine and trans was missing. The original 10 bolt rear end was broke which kept the car from becoming a roundy round car. The last owners even spray painted "00" on both doors and roof and "STP" on both rear 1/4's. It also had the drivers window down for all of these years and animals lived inside of it. Suprisingly, my son found the factory build sheet under the front seat.
Just installed the Pypes exhaust my son purchased from Performance Years Pontiac Parts today (Christmas Day). He got the Street Pro all stainless steel system including stainless steel 1" Pypes band clamps. Wow does it sound good with the small Melling cam ( same as the Summit 2801 cam) the stock 1975 low compression 400. Glad the weather was ok and warm enough to work on the GT-37 on Christmas Day. The install was pretty easy and the pipes fit like a glove. Just used regular hand tools.