i got a 89 full size blazer with a 350 its tbi and it blew a head gasket and i got another engine sitting around its a 86 350 but i was wondering if i could just swap the intake off my 89 and but it on the 86 engine without swaping the heads over thanks in advanced

 

Nope, the center bolts on the heads are different.

On you're 89 TBI heads the center 4 manifold bolts go straight down, on the 86 the manifold bolts are all angled.

You can pick up a good manifold like a Performer series intake from Summit for around $100 and use a TBI adapter plate, or swap the heads.