Hello Larry and welcome to the Stovebolt!
Lots of old Chevys have had V8s installed. What year truck is it? What kind of subframe is it? Is it complete with crossmember, front suspension and steering? Are motor mount brackets already in place?
I suggest you peruse the gallery and look at every truck similar to yours as many have V8s and some have links to pictures, etc.
Also search this forum for threads about this topic, especially the HiPo forum.
Other websites such as
the HAMB are all about engine swaps.
Good luck!!