primary factor to consider is rod and rod bolt strength in my opinion, especially if you want to rev it.

Piston speeds in an ls/vtec exceed all vtec engines by a fair amount and the poor rod stroke ratio makes it a short life engine compared to something with better geometry and lower piston speeds. By that I mean a good ls/vtec rebuild might go 70,000 to 100,000 miles before it gets sloppy, while you might get 130,000 on a rebuilt gsr. Also depends on how hard you beat on it. Figuring most here drive a bit hard, the 200,000 mile mark is hard to get to, at least without drinking as much oil as gas.

I don't think ls/vtecs are worth doing unless you get rid of the ls pistons and go with vtec pistons. Ideal set up is forged internals and pushing 12:1 compression and putting some cams in to make the most of the increased compression. you also will need a 2.5-inch exhaust system and headers. Tuning is a must, at least if you are adding performance cams. Type R cams will do if you don't go over 11:1 but they don't really have the duration for 12:1, so you'll want some of the bigger sticks.

Do a good oil line setup to ensure no leaks.