[mysticmissle]

going to be installed on a 71, but what is best way to make this happen? down pipes, don't have to be stainless, but rest of system is. thanks in advance

[KSZR]

I have Pypes system on mine. You will have to grind the bell of the exhaust pipe down to clear the manifold bolts and also make contact inside to seal. Pipes told me to draw with a magic marker inside the headpipe and bolt up. The magic mark will rub off showing if you are sealing against the manifold. If not you need to grind more off the bell.

[mysticmissle]

the 2.25 flanges will clear the 2.5'' pipe if i neck down the bell?

[KSZR]

Yes

[Scarebird]

The nuts are a PITA to turn though. GM used a 2-1/4" for the first foot then welded it in the 2-1/2" pipe.

[mysticmissle]

just to tidy this up, they required little to no reshaping of the pipe bell. I did end up using allen bolts about 1.5'' long not as easy as studs but it sounds good. I did have an exhaust leak when i first started but that was because it did not seal the flange at one of the points, loosened it and just tightened the 3 more evenly and it sealed up great. Ill post some pics w pypes street pros and x pipe. its a great system. highly recommend.