4.3 / 700r4 into a 64 information needed

[fs64]

We have a 64 short stepside that was a 230 IL6 w/ 3spd man.
I got a great deal on the 4.3 / 700 r4 rebuilt pair. Although it's not a sbc it should be a good daily driver combination for my son's truck.
Has anyone done this swap that could share their experience? My biggest concern is the motor and frame mounts for the engine. Is there any factory combination of parts that will get this bolted in simply or will I need to fab together mounts?
I have the original 6 mounts as well as ones from an 88 1500.
As always any help would be greatly appreciated.
Thank you for your time.
Todd