The 61 did come with a V8. C10= 283. Big trucks= 348. As Jerry says, mounted up front and truck bell housing. Your 69 may have side mounts used with "perches" or "towers" and three hole motor mounts. Don't know what trans you are using. 4 speed is cantilevered probably and needs truck bell or other depending on what cross members you have now. You may need the universal tubular one added as said. Pretty easy to do all that. Be sure to double check what threaded motor mount holes you have on that "special" motor before proceeding. Obviously you will need to hang motor in there with perches to see where to attach them and what mods/spacers are needed. Mock it up to see all the clearances that are necessary. Radiator, steering, exhaust, firewall, etc., etc.
Have you done this kind of stuff before?
