About to refit cab, but...

[Captainfab]

The '60-'62 frames do not have holes in the frame rails for side engine mounts like the '63+ frames do. Without knowing exactly what side engine mounts were used on the OP's truck and in what relation to an original installation it is, it is quite difficult to say what if any clearance issues he may have.

Originally Posted by LT1 Burb

I had a 66 with a 700R4 in it and had no issues, you should be in the 2 front motor mount holes .

[1G1YY]

Originally Posted by Captainfab

The '60-'62 frames do not have holes in the frame rails for side engine mounts like the '63+ frames do. Without knowing exactly what side engine mounts were used on the OP's truck and in what relation to an original installation it is, it is quite difficult to say what if any clearance issues he may have.

What you say makes total sense...there are no extra holes on top of the chassis, only those that were drilled for this front end swap.
The perch style mounts are fixed by 2 bolts thru the top of the frame and a 3rd bolt is attached to the later model x-member.
The rear top vertical mount bolt is in line with the front x-member horizontal bolt.
As I said earlier the only thing I do know with respect to engine for or aft location is that the engine fitted to my truck had a HEI distributor fitted to it, so I can only assume that the engine was located further forward than those who cannot fit a HEI in their bay because of firewall proximity.
I am hoping that this and the 3degrees or so tilt that I have will allow the 700R to fit.
I will nevertheless grind back the thin 1/4 or so inch lip before attempting to refit the cab.
Thanks again to those who have offered their take on this.