Brake ID questions

[Halogin13]

Hi All.. Need some help ...
1987 V10 Silverado, 5.7L TBI....

I have a 14 bolt rear end, and 8x6.5 bolt pattern......
1)was this a setup that was available originally? Or has there been an axle swap?
2)Theoretically, I should have a JB5 setup, right?

I want to replace my brake shoes, but without opening the whole thing up and taking out the axle etc., is there a way to confirm shoe size from the attached pics?

[zieg85]

That axle was swapped in.  The brake drum should be stamped with the diameter.  I would be willing to bet if you go and ask for rear brakes for a 1978 C20, you should get the right ones.  After 81 GM 8 lug axles were the semi float unless you had a 8600GVW

[Halogin13]

Thank you !