MountainStone

I contacted BlackBear Performance and will soon be getting a tune for my 8.1L Avalanche (two, actually: one for towing and one for performance). I hope to travel to Lake Havasu city for an in-person dyno tune, but if it doesn't work out I'll settle for the AutoCal tune via logging and email.

Anyway, I'm wondering if there are any mods I can perform to the truck that would maximize gains from a custom tune. I'm willing to spend ~$1K if there is a decent return. The truck is stock other than a flowmaster cat-back.

Would a cam change be worth it, even if I leave the heads/intake stock? It's my understanding the stock heads and stock intake are super restrictive on this particular engine...

Thanks for any input.