1. The Vortec heads do not have an exhaust crossover. Therefore there is no exhaust available to the EGR valve unless you use external plumbing from the exhaust manifold. There is also zero heating of the intake manifold except by the coolant in the thermostat crossover, and where the manifold touches the coolant ports at the back of each head. I'm not sure how this is going to work in cold weather.
2. Most Vortec intake manifolds don't have EGR passages. The TBI / Vortec manifold does.
3. Dorman sells reproduction exhaust manifold, and EGR tube to put a functional EGR back on the Vortec-headed engine. The price is not horrible, but being Dorman, it's all Chinese and you WILL have to resurface the manifold before bolting it on because it WILL be warped.
Manifold = Dorman 674-218 (verify that it will work with your O2 sensor. It may not be tapped for an O2 sensor)
Exhaust tube = Dorman # 598-200
They suggest an EGR valve that crosses to Standard Motor Products #EGV327
4. The Vortec-to-TBI manifold must be made out of cast 14-carat gold. It is enormously expensive.
5. Based on the cost of the Vortec-to-TBI intake and exhaust manifold, the EGR pipe, etc, I'd be looking at EngineQuest aftermarket heads. They've got an exhaust crossover, you should be able to use your existing TBI intake manifold, and exhaust manifolds, which would save you a huge amount of money--about the same as the cost of the new pair of heads.
https://www.ebay.com/itm/CHEVROLET-...ash=item27f225a521:g:VS4AAOSwkNZUkw~G&vxp=mtr
If I'm understanding the photo of the heads, they've even got the angle of the center bolt holes correct for TBI use.
For the record, I stuffed a '91--'93 B-body service replacement crate engine into my '88 K1500. (Used to be sold as GM # 12513151, but long discontinued) Roller cam (ultra-mild), swirl-port heads, and flat-top (instead of stock dished) pistons for a small compression-ratio boost. I added Edelbrock 6667 "tubular exhaust system" (emissions-compliant headers.) ZERO tuning, runs great. Not much additional power (a little) and not much improvement in fuel economy (a little.)
