88-91 Light duty to Heavy duty brake conversion worth it?

[AlainRenteria10]

I have light duty 1" brake rotors. Would it make sense to upgrade to 1.25" heavy duty rotors, along with 3500 calipers, 2500 pads?

Spindles Junkyard $54
-Bearings $22
-Rotors 56258FZN $144 Are 3500/1500 same?
-Calipers $65 raysbestos 3500 vs 1500 size?
-Brake pads need. Z36-369 ? $60
3500? 8 lug vs 6 lug
-Caliper bracket?
-Brake lines?

Here's what I've come up with so far. What do y'all think? Should I do it?

 

[evilunclegrimace]

A bit more info is needed. 2wd or 4wd?

 

[WILWAXU]

I did the swap with new parts when I lowered my truck (new drop spindles). I ordered everything for a '92 truck, which all had HD brakes. https://www.gmt400.com/threads/swap-meet-slam.42821/page-2

 

[Schurkey]

Look in your glove box at the build sheet decal. What brakes are on the truck now? JB3, JB5, or something else? Based on the 1" rotor, I'm guessing JB3. Smallest, weakest brakes offered on a GMT400.

I have an '88 that came with light-duty JB3 brakes. Narrow rotors, small caliper pistons, horse-**** Leading/Trailing shoe rear drums.

Swapped to a light-duty K2500 six-lug rear axle having much better and larger Duo-Servo rear brakes.

In the process of swapping to K1500 "extended cab" JB5 front brakes. Thicker rotor, bigger piston in the caliper, BIGGER MASTER CYLINDER AND BIGGER POWER BOOSTER. I simply grabbed the entire front suspension from a JB5 truck, and then took the master and booster from the same vehicle.

DO NOT swap to bigger brakes without also going to the bigger master and booster. Remember that you need a step-bore master (Quick Take-Up master cylinder design) if you're using the JB3 or JB5 "Low Drag" calipers.

3500 calipers are probably not "Low Drag", you wouldn't need the QTU master. I have no idea how they fit the various steering knuckles.