Newer axles on my 72 K20

[budman k20]

Hi,

I'm just about done rebuilding everythiing on my 72 truck and I found out my front diff has a bad axle u joint on the driver side. I found a good deal on front and rear axles from a 74 chevy ff rear and lockout hub front. I was hoping the front would be a bolt in and the rear only requires moving one shock mount. Can anyone help me out with this swap? I did search before posting but didnt find anything that answered my question. I need to make a decision on the 74 axles by this weekend. Please help me I'm new to 4x4 trucks.