TOPIC:

Hello,

Any help appreciated. In the process of installing the exhaust with new crush rings the collars were tight, but there was still considerable movement in the pipe. Are there oversized crush rings available or?? I noticed the last owner had stuff some fiberglass substance around a few collars. Thank You.

I suspect the back half of your pipe may be mounted too low and as you tighten up the collars, you're crushing the seal rings on the top half and not on the full circumference. I'd carefully pull off the collars and have a look at the rings and see if in fact they're not crushed evenly.
You might try mounting the pipes without the rear half of the exhaust system in place, then locate the rear half and see if the mounting bolt hole for the rear half lines up with the frame mount location.

Lots of guys have been having trouble with the exhaust mounting. Usually it's the aftermarket stuff that needs some tweeking to get it right.

In behind the "collars" are 2 x 1/2 sleeves for each pipe, these pull down on the lip on the pipe and push it onto the crush rings, with my '79 the 2 outside sleeves are a tad shorter than the other 4, don't mix them up, with the sleeves in they should clamp down firm

Thanks Kawboy, I can run it briefly, note the location of the leaks, and check the crush rings. Didn't think of the elevation of the rear of the header, my one bad leak is at noon on one cylinder.

Thanks KZA13, did not realize these 1/2's could vary, have to be at least part of the issue.

Interesting issue and several good comments. When I had the stock exhaust I did not notice any difference in the width of the 1/2 collars but that doesn't mean they didn't differ. However I do remember clearly that I did not register any sets of mounting hardware to any specific cyl. Installation of the DG was similar and I've had if off several times over the years. I used what ever collars I picked up out of the tray they were in. I did not keep them referenced to any specific cly. How the 1/2's are installed is crucial as the manual will suggest and as dictated by their asymmetric shape. I used "scotch-tape" (no pun intended) to keep the 1/2's in place for mounting. The tape has no affect on anything other then your patience being far less taxed !