You can put a van straight axle under your car and it will work fine. I built one and I have driven it at the drag strip in the 10's at 120 with no problems. I use the original 10 inch drum brakes. I had springs made at a local spring shop but only because I had limited room forward of the axle.I used a 66 Dodge A-100 but I am sure you could use an econoline or chevy light van Ibeam axle. I bought mine at a junkyard for 100.00. I had the guy at the yard torch off the frame mounts and got the shackles also. After I put it in I tightened down the original brake lines to the 65 Plymouth and bled the system. The brakes worked with the original rubber brake lines. I have driven the car on the freeway and in town. The brakes are a little grabby and I am not going rallying with it but that's not really my kind of thing anyway.