My 93 yukon is JB5.....But Appears I have 11+" shoes..... my drum is over 13" in diameter..
... 6 lug...
Three possibilities for GMT400 rear drums:
254mm (10") Leading-Trailing shoe drums
11.x Duo-Servo drums
13" Duo-Servo drums
Pretty sure the 13" drums were not available on 6-lug trucks, and 254m drums not available on 8-lug trucks.
As said...measure the inside diameter of the brake drum to find out for sure. You have the 11.x drums--a
very good system if kept in proper operating condition.
Do yourself the biggest favor possible and ditch the rear drum brakes. Head over to littleshopmfg.com and purchase one of their rear disc brake conversion kits. And I also highly recommend doing the master cylinder upgrade as well. Easily one of the three best things I've ever done for my truck.
Bottom-feeder junk, probably with less stopping power than the 11.x drums he's got now.
If he's still got the low-drag calipers, the Little Shop of Horrors master cylinder "downgrade" won't be correct either.
MOST "disc brake conversion kits" are crap. Not all, of course...but the good ones will be very expensive. Better to grab the disc brakes from a newer-model truck of
at least the same GVWR as the truck they're being installed on.
If what you removed
wasn't working properly, especially if it was the ultra-crappy 254mm leading/trailing shoe garbage, it's no surprise that a properly functioning disc conversion feels "better". One problem with the Little Shop of Horrors disc conversion is the screwy caliper mounting system.