1960 to 1972 front axle swap

[Blue Ox]

I know similar topics have been discussed elsewhere around here. Maybe it's just me... but I'm not coming away with a good sense of what the interchangeability (is that a word?) of early and late model front axles is.

I have a 1960 GMC 3/4-ton (K1502) that I'm fixing up. Like a lot of folks, I'd like to upgrade to disc brakes on the front, but I have the closed-knuckle front end and it's looking like going with a later model axle is going to be the most efficient method.

I have a line on a complete front axle from a 1972 K20 (correct gear ratio and everything). Can anyone give me a clear summary of what I can expect to have to modify (if anything) in order to get that to work?

I'm not worried about modifying the brake system to work. I can figure that out. I'm just wondering about the physical compatibility between the two axles (spring perch locations, any offset in the location of the diff housing, etc.).

Thanks!

[Clyde65]

K20 to 72 k20?

Should be an easy swap, c20 to 72 c20 hasb een done a ton of times.

[Blue Ox]

Yes... Sorry... Had to correct the first post. I'm going from 1960 K1502 to 1972 K20.

[andyh1956]

Why not just use the '72 frame & leave all the axles & suspension components in place? You will gain the indention for the p/s gearbox.

[Blue Ox]

I don't have access to the whole 1972 frame... just the front axle assembly.

Besides, my '60 frame is in good shape. Spent some time cleaning it up and putting a nice coat of Chassis Saver on it. I'd hate for that to have been a waste of time.

Also, I've driven the truck in years gone by. The manual steering was never a real hardship. I just want to switch to disc front brakes. Call me crazy, but I don't like having to guess which direction the truck is going to go when I hit the brakes

[downeyballz]

measure the spring perch width, there probably the same. should bolt right in as there both dana 44 front axles. then its just small stuff like brake lines and steering. you will need to add a proportioning valve.

[padresag]

Originally Posted by Blue Ox

I know similar topics have been discussed elsewhere around here. Maybe it's just me... but I'm not coming away with a good sense of what the interchangeability (is that a word?) of early and late model front axles is.

I have a 1960 GMC 3/4-ton (K1502) that I'm fixing up. Like a lot of folks, I'd like to upgrade to disc brakes on the front, but I have the closed-knuckle front end and it's looking like going with a later model axle is going to be the most efficient method.

I have a line on a complete front axle from a 1972 K20 (correct gear ratio and everything). Can anyone give me a clear summary of what I can expect to have to modify (if anything) in order to get that to work?

I'm not worried about modifying the brake system to work. I can figure that out. I'm just wondering about the physical compatibility between the two axles (spring perch locations, any offset in the location of the diff housing, etc.).

Thanks!

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