You need the bezels and headlight buckets to make the switch. A few people on here have posted their change from 80 to 73-79.
I like them, and they are different, but...
As far as parts, I have a 5 piece repair kit here:
http://store.73-87chevytrucks.com/me...tegory_Code=C1
It comes with a partial floor, if you want a full pick standard, if the whole floorboard is shot, get the extended. You can click the link and see a customers repair...
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Chris Lucas
1973 Chevy C-10
1978 GMC Jimmy (2WD) - SOLD
1987 R10 twin turbo LS
1991 R3500 SRW CrewCab
1985 K5 diesel swapped project
1989 K5 2WD conversion w/ Vette susp Project
Captkaos Customs
73-87chevytrucks.com