Most likely 75 to 79 would be for sure exactly the same. 80 to 93 will work but there may be minor snags as you get into it. You also should stay with a 3/4 ton frame. However a 1/2 ton can work. 72-74 could also work. For the most part the 72-93 are very similar. Nothing that some drilling and minor fabrication can not fix.