I have been kicking around the possibility of doing a cam swap in m 97 7.4L.
1. That'll have a roller cam/lifters with a thrust plate. Wonderful set-up. I converted my boat Mark IV 454 to the Gen 6 thrust plate system. Requires a different timing set than the non-roller-cam engines. Of course, you've already got that stuff.
2. The Vortec heads will have valve rotators under the valve springs. You probably don't want to install stiff valve springs on the rotators. You'll need 16 valve rotator eliminator shims. There are two styles I'm aware of--one part number for regular valve springs, one part number for beehive springs. The shims came in 8-packs when I bought mine, so I needed two sets.
3. The INTAKE valve guide bosses have a small radius where the valve spring pockets are cut. This radius can interfere with the rotator eliminator shims. Be sure the shims fit flush on the valve pocket, and grind clearance in the radius if needed. I had to touch-up two intake guide bosses on each head. The other two cleared without rework.
4. I converted the valve train to an adjustable style. Not absolutely required, but kinda nice. Various vendors sell the "special" rocker studs for a screw-in system, no machining needed.
5. Buddy of mine has a Vortec K2500. One of the best upgrades he says he's ever done was to scrap the original muffler. VERY restrictive. He's since added headers and custom-bent exhaust, but the muffler change made a big difference by itself.