Is this a JB5 rear brake drum?
 

Please see attached photo below, is this a JB5 or JB3 rear brake drum?
Les

Re: Is this a JB5 rear brake drum?
 

looks like JB3 brake drum

Re: Is this a JB5 rear brake drum?
 

If that's off your truck, and your truck was originally a manual brake job, then it's a JB1.

JB3 is the smallest power brake system.

Per the chart JB1 and JB3 use the same drum.

K

http://i1016.photobucket.com/albums/...ase87-1001.jpg

Re: Is this a JB5 rear brake drum?
 

Thanks, Keith, this not off my red 86 stepper. This is from another 86 chassis I purchased, which has the JB5 front brakes on it, ( however do not think the front suspension is original to that chassis, maybe from Sub). Guess I can remove drum and measure, and my truck is at body shop so can not compare to it's JB3 drums.

Thanks,
Les

Re: Is this a JB5 rear brake drum?
 

Ah - I see.

Yes - you should be able to measure the width of the friction surface/shoes.

JB3 = 2"
JB5 = 2.75"

per the chart.

K