I have generic glaspacs on my Suburban with Fentons. They were installed close to the front with a bunch of open pipe to the back. They were obnoxious. I installed a pair of Walker resonators close to the rear. It still has that mellow glaspac sound running through the gears but once I get into high it is relatively quiet.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.