Brake Caliper issue

[smfreema]

i bought a used set of 2.5 Western drop spindles for my 84 chevy truck. I dont think the stock brake calipers will fit correctly? Bolt holes aren't lining up? Same 1.25 rotors where on these spindles....Any recommendations?
Am i missing something? Please help!!!
Thanks

[smfreema]

Let me ask this....do different year trucks have different calipers? Could i have spindles from truck pre 81 and my 84 calipers wont fit? Or could i have calipers on this truck that are different? Could i have wrong spindles? They bolt up fine? I put new ball joints on....I"m not sure where to start figuring this out as no one seems to know...Any insight appreciated..
My caliper bolt holes are not lining up by a good 1/4 inch....

[Captkaos]

Pre 1980 1/2T trucks only came with HD 1.25" rotors, 81-87 had 1" or 1.25.  The brake lines should work.

[84burb]

Looks like you've got some research to do. 
I don't know what your truck is but I'm going to assume 1/2t.

Western lists separate part numbers for the 73-87 C10
1" rotor - 2 1/2" drop (part # 13200)
1 1/4" rotor - 2 1/2" drop (part # 13100)
There is also a different part number for 88-91 C1500 - 2" drop spindles. (part # 12400)

The C3500 series have different spindles also.
73-87 - 3" drop (part # 13600)
89-99 - 2" drop (part # 13700)
==================================
I see 4 different applications for calipers on 2wd 1/2t pickups 73-87.
73-78
79-80
plus 81-87 have 2 different caliper apps depending on rear brake size

88-91 have 3 different caliper apps depending on the production option.

Clear as mud?    
Sorry I couldn't be more help but you are going to have to get more info on what you actually have in hand.

Casting/part numbers on your spindle and a call to Western Chassis (Tech 888-999-9139) may give you the info you need.
Remember, Google is your friend. Major auto parts sites are great for finding what stock part numbers interchange with a little time searching.