I dig V8's. It's neat to put them in old vehicles. It's what gearheads have been doing since 1932. All issues of doing that with your stock body and frame can be addressed.
A restomod is a good way to preserve the old truck's integrity and it's timeless look. Albeit it won't be stock enough for many members. That's OK, they will still help you.
That motor you show is not all that cheap. V8's are kind of near a dime a dozen still. That one is dirty, ugly

, may be stored outside, no carb covering and CAN'T HEAR IT RUN. DON'T BUY A MOTOR YOU CAN'T HEAR RUN AND CHECK SMOKE AND CHECK COMPRESSION AND VACUUM, ETC. Don't do the "I can always rebuilt it" bit. Buy a good runner. I have bought whole trucks to be able to drive, hear and check motor and trans, sold the parts like a junk yard does and came out with free motor and trans, steering and other items. Not everyone has the space and time for that, I realize. Just be sure motor runs and so on.