ranger94

most of the info on the unibody is correct i own a 61 unibody sb that im restoring right now and the problem with them was that the cab and bed flexes at different rates so when it was loaded down the tend for the doors to not open or close although my grandfather had it loaded down to where the back bumper was almost draggin the ground and never had any problems with it.but the unibody was used 61-63.in 61 all were unibodys starting in 62 and 63 only shortbed 2wd were unibodys.i love the unibody its a great looking truck although its not a very good design only 2 bed crossmembers that go from wall to wall and bed mounts directly to frame and for support theres what some ppl call a torque box that sits right up against the cab.if you want to check out more on these trucks go to fordtruk.com its a great site dedicated to only 61-66 ford f series

the pinging is prolly carbon buildup the ohv 4.0 were bad bout this dont know bout ohc go get some seafoam and try that