Motor mounts will be the same, I beleive even the LS series engines still use the same mounts, too. A bit of clarification should be made concerning the "Vortec" engines, as there are 4 different engines that have used that name over the years, so it can get confusing. The first one was the 4.3 V6, as used in the S10. The second was the late production 350 with the central port injection, similar to what the V6 had. That one was used in the late '90s GMT400 trucks, also some '00 Tahoes, 'Burbs, and the 3/4 and 1 tons built on the GMT400 chassis. Then came the Vortec 4.8, 5.0, and 6.0 (and now including the 6.2 Vortec Max) that are used in the GMT800 and GMT900 trucks. Those are built on the LS engine block, and share very little with the earlier engine. There was also a Vortec 8100, which was the new Big Block, which was not very popular.
The 350 Vortec was/is also available in an aftermarket crate engine, and is set up to use a carb. So intakes are available if you wanted to use that engine and swap to carburation. You just want to make sure you have the right manifold, as they don't swap very well with the older heads.
