73 K5 to 3/4 swap???

[jmanthony65]

I bought a 73 K5 with 35s but it still has the 3.07 gears needless to say it doesn't exactly get up and go.. I was thinking I probably could pick up a used set of 3/4 ton axles with 4.10s already for around the same money as swapping in gear sets. I was wondering what year models if any will pretty much drop right in or what complications or issus I will need to look out/prepare for? I welcome any opinions and help...

[TheWhiteElephant]

If I'm not mistaken, this will be a direct bolt-in if you get the pair of axles from the same donor truck. I swapped in a 14 bolt ff rear from a '79 3/4 ton truck to a '79 K5 and it was a direct bolt in. Did it all in a few hours. To be sure, just take a measurement from spring perch to spring perch. I did have to get different U-bolts (the axle tubes on the 14 bolt are larger) and you are going to have to get another U-joint for the shaft. I forgot what the part number was but it is readily available at the parts stores. I didn't swap in the front axle assembly because I found out it was shot when I opened it up.

[Altec]

The spring width is the same on 3/4 ton, it is 1 ton that is different.