Thats not a Vortec block. They didn't exist until 1996. In any case, short of a few slight variations, the 1986+ blocks are all the same. Bore/stroke, one piece rear main, provisions for roller cam, etc. Have we been over this before?
Back to original poster...Vortec heads are a good swap, but as I said, can be expensive. Some on here must have gone with a carb to TBI adapter on a dual plane intake, that is probably the cheapest route. My edelbrock carbed vortec intake I bought a few years back was $150 new. How much are adapters, and how much work to make the throttle/TV cables work is the question with that idea.