New issue with disc brake conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

tdangle · 12-01-2021, 11:21 PM

Converting a 70 C20 power drum to power disc. Basically changing it to a 71 C20 with power disc brakes. Swapping out the dual 8" booster to a 10" dual booster as stock with a 71 C20. Problem is the mounting Frame is 3 1/2" from the firewall and it looks like it needs to be 5". the rod coming out the back of the old booster to center pin is 3 1/4" the new booster's rod is 4 7/8" to center of the pin. Did GM change the bracket to a longer one? Can anyone verify?

**leddzepp** · 12-02-2021, 01:39 AM

Sounds like one setup is Bendix and the other is AC Delco.

12-01-2021, 11:21 PM	#1
tdangle Registered User Join Date: Mar 2005 Location: Jurupa Valley, Ca Posts: 1,211	New issue with disc brake conversion Converting a 70 C20 power drum to power disc. Basically changing it to a 71 C20 with power disc brakes. Swapping out the dual 8" booster to a 10" dual booster as stock with a 71 C20. Problem is the mounting Frame is 3 1/2" from the firewall and it looks like it needs to be 5". the rod coming out the back of the old booster to center pin is 3 1/4" the new booster's rod is 4 7/8" to center of the pin. Did GM change the bracket to a longer one? Can anyone verify? __________________ Terry 1970 Custom Camper/C20 , GM Crate 350/7004R, Dana 60, factory AC

12-02-2021, 01:39 AM	#2
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,036	Re: New issue with disc brake conversion Sounds like one setup is Bendix and the other is AC Delco. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.