Yes it's for the two barrel integral head 79-85 fullsize trucks I guess if your handy and can make a bottom plate for the one barrel integral head it would work on those also.
I bought it on ebay from a speed shop that was closing and putting there NOS stuff on Ebay, I called hooker and they had 10 sets of gaskets left they tried to sell them all to me. I ended up paying like $12 for a set.
The factory manifolds on these engines run big bucks $500 mine was leaking just never got around to installing it and then sold my truck.