The name of this site is LS1trucks, not TBI350... We are biased towards ls based engines for logical reasons. The 350 you have isn't even the same as an older 350 because of the TBI. Sure, you could slap a different intake and a nice carb on it and be better off. You could cam it, get a stall in there, get at least 4.10s, a custom tune.... Then you talk about a supercharger. A supercharger and supporting mods is going to cost a pretty penny, which you said you don't have.

I will be honest with you. For the money, a 6.0 swap would be cheaper, more reliable, and better on fuel than your TBI 350 with the mods you're talking about. You can get 500 rwhp out of a NA 6.0. Ask skeet, he's close. Myself, I'll stick to my 5.3 with a little shot of giggle gas... And it'll outrun you on motor. No cam, no stall... Just bolt ons.