I've been using these:
https://www.summitracing.com/parts/wlk-35780 and these:
https://www.summitracing.com/parts/wlk-35460 for exhaust hangers on projects going clear back to Patch, the Wonder Yota. I orient the rods such that they are parallel to the exhaust tube and when cold push against opposite sides of the rubber piece so that as the system grows with heat the rods just pull back thru the rubber. This gives me about 2" of thermal growth allowance. They are a little space consuming, recommend buying two rods and a rubber piece for mock-up before commiting, but I really like them. Lots of compliance with no noise transmission.
I have discovered a downside to these and that is that you can't make the exhaust tube side rod too short or it melts/burns it's way thru the rubber part.
Didn't help that the one that suffered that fate is about 12" downstream from the cat. doh!!! I re-made that hanger to have more length by picking up the tube from the bottom rather than the top and it's been working ever since.
A concept that MISF came up with, that I've been using for 20+ years, is to make the exhaust system come out in sections. We use 3 bolt flanges, but do NOT butt the tube ends together. the upstream flange is set about 1/2" further upstream from the end of the tube. the downstream flange has it's ID opened up to fit over a piece of exhaust tubing that has been expanded to be a slip-fit over the upstream tubing. The downstream flange is welded to upstream end of the slip-fit. I've never used a gasket with these connections. I have used high temp RTV with good results.
I used to ask for the expanded section to only be 3/4"-1" long, but now I just get as long of expanded section as I can and cut it into ~3/4" long pieces. Bolting the expanded piece (with it's flange welded on) to the upstream flange gives a nice 'socket' to plug the downstream tube into. When ready it's easy to just weld the downstream tube into that 'socket'. I try to buy flanges with dedicated holes rather than slots. Even with the now more common V-Band clamps for exhaust systems I find that I prefer the 3 bolt flanges. They do take longer to make, but they fix the rotational location where the V-bands don't. I used to have a SW generated jpg of this, but I'm not finding it. Should I make another one?
About the bolts holding these joints together. Most can't or won't believe me when I tell them to use a carbon steel bolt with flat washers only, and a
Brass nut. You won't need lock-tite or lock washers or anything else. Just take the bolts up to snug and drive it. They do not come loose. In 20+ years I've never had even one nut work loose.
