I have my 70 GMC C2500, now a C1500, air bagged front and rear. Because of my 6" drop, I also did not have the room to have my exhaust travel over the rear axle. I mounted my air pump and tank on the drive's side outer frame near the cab and the bed. For ground clearance I used shorty headers to keep the exhaust pipes close the the floor of the cab. This is not ideal for heat in the cab, but I use exhaust wrap from the collectors to the just forward of where the exhaust exits over the frame. The wrap works very good to keep the heat out of the cab.
I'm using the Ride Tech Rear StrongArm System and Rear HQ Shockwaves air bags. I used this system to replace the 3/4 ton 7 leaf rear springs on my GMC.
https://ridetech.com/product/60-64-g...le-adjustable/
https://ridetech.com/product/1963-19...stem_11337199/
My exhaust pipes (2.5 inches) go through the tubular cross over from Ride Tech. The next two photos are of the passenger side where the exhaust pipe crosses over the frame and follows the frame over the rear axle. No holes were drilled in the frame to do this. Doing this does not allow enough room for mufflers to be mounted before the rear axle. I did not want to mount the mufflers under the cab because of heat concerns. My muffles are mounted in the rear near my aluminum rear gas tank. Sorry don't have a picture of those. I do not have any interference problems with the tires and exhaust.
This is looking forward from the rear on the passenger's side. Look in the upper left corner and you will see the edge of my Flowmaster muffler. The pipe exits the muffler and is tucked nicely under the rear bumper.
You can see how the exhaust exits the rear bumper. The mufflers are mounted high so they are not visible from the side of the truck. The exhaust sounds good, loud enough to have a presence but not annoying and NO exhaust rumble. I don't remember the Flowmaster number. They are not the smallest ones nor the largest. But they do a good job of sound control.
