(off my 74)i have a setof faily new exhaust pipes from hooker headers the size is 2 1/4, your stock ones are 2inch there pretty much brand new, no rust, the only thing is that when it was new the pipes came in two pieces, so when i installed them you have to clap them together...this in turn pinched the two pieces together and pretty much impossible to get them apart....not a problem though all u have to do to install is drop your crossmember and slide them in.... just get urself some regular long headers and bolt it all up, i also have one flow master muffler....... this system is nice an makes the stock exhaust sound like a puppy dog...but anyway im rebuild the motor and putting 3 inch on it : ) let me know if ur interested ill shot some pics your way...my email freemotocr250@yahoo.com

 

Yes. It will cut the underhood heat significantly. Not to mention that Jet Hot w/ warranty new headers for life if they do them.