1997 3/4 Surburban

Good question. Which axle do you have in rear? Does it have hubs passing thru wheels or are they flush with drum? (10.5 FF or 9.5 SF) Also if you make this change you will need to change wheel cylinders, master cylinder and and it may mess with ABS calibration too. I am curious, why do you want the unpgrade?

----------------- TheSnoMan.com

They are flush with the drum. I considered upgrading due to the poor braking of the smaller brakes. Also, what are the specs for turning the drums.

Actually your brakes are not that small. You might consider changing wheel cylinder to one with about a 1/16 to 1/8 inch bigger bore to apply more clamping power to brakes, The larger 3.5 inch drums (I have them on my 2000 K3500 SRW) asfitted on the 10.5 FF axle not the 9.5 SF you have and I am not sure that they will fit your axle. I have done this wheel cylinder trick before and it can help a lot sometimes. My guess is that as it sit very little braking power is being done by rear axle now and shoe last a long time. On turning drums, I have mixed opinions on that. Usually it is around 060 to 090 overized and it is usually stamped into drum too. The reason I am not a fan of it is that if you turn them because they are warped you wind up with uneven metal thickness and a thinner drum which is more prone to warp again. Basically when i do a brake job I will have the lip only turned out of drum, not whole surface and if surface of dram is badly grooved, I replace it.

----------------- TheSnoMan.com

Thanks for the info, Pete