since owning 2 69's I know that 68-72 is interchangable as far as suspension goes but I dont know about my 65. I'm going to start getting the parts I need to do the frame/suspension on the 65. is 64-66 interchangable as far as suspension/rear end, etc. thanks

I think most 64-67 stuff is interchangable, with the exception that some 67s had 68 (wider) rear ends.

Michael,
Suspension parts should all mostly interchange between 1964 and 1972, except things like the steering center link (but there are two early ones), probably the idler arm, coil springs (64-67 fronts, 64-66 rears), and the upper-rear control arms (65-67 will work, maybe 64 too)...

Sway bars will interchange (64-72)...

The rearends are wider starting in 1968, but 68-72 rears will still bolt-in. Mounting locations the same, only possible tire clearance issues as the axles are about an extra 3/4 inch longer on each side. This can usually be compensated for with more Backspacing on the wheels...

Front control arms and rear lower control arms interchange... Two different styles of bushings on the front-lower control arms, but either will work with your frame, (just need the proper bushings for the arms you use)...

THe upper eyes on the 64 rear end are smaller than the 65-67's. I think you can get a different bushing thing(forgot actual name, sorry) ANd also some Im not shure if all but the spring mount pads are different on the 67 rear ends. this was an experimental design for 67 I hear. Im having a hard time trying to find a 67 12 bolt for my 67. I already have the springs specific for 67 so I need the 67 rear end.