Casey,My truck started life as a 75 K10 w/a 350 the body was junk so I bought a Texas 84 cab and from Gm new stock built a 80 silverado front clip.
When I bought my 6.5 I also bought a Banks Turbo kit for a 84 6.2.
The odd part is that ever thing fit just fine lower hose and all, the air filter box was a bit of a challenge with the batteries at a right angle to the fenders instead of parallel like the 84 but it fit, barely.
I even used the 75 a/c box and 350 hoses,fit fine.
The only thing I had to change was the upper rad hose, it was way too long,shortened it a tad and all was well.
The 81 gasser must be a case all its own as far as radiator and front support.
The worst expense was puting the 6.2 rad tanks on a 454 core, that hurt.
anyway good luck on your turbo project, I hope its all you expect it to be.........Merle