If your talking 4.3 there are a number of manifolds available check out sumitracing.com I just looked and edelbrock makes a couple different performer intakes for it 2 or 4 barrel different powerbands and such
this is the one for the vortec 4.3 the heads are a little different than the older ones
these engines are carbon copies of the small block v8 you can actualy run one off a v8 distributor we did once in a pinch. there are countless trans combos that bolt to the 4.3 check into older k5 blazer and pick up stuff, the front drive shaft comes out on the pass side. most small block v8 parts fit and work on the 4.3 good torque you'll have to watch your gearing these engines don't like to rev like a 1.6