Welcome and nice looking truck!
Sure would be nice to know cam specs, what pistons did he use, were the heads ported, did he up the pressure on the tbi, has the throttle body been modified, is the fuel pump stock or modified, has it been rechipped???????
It didn't perform in what way? No power, idle issues, starting issues, backfire,.........need some clues man
My hopes would be that he built a badass bottom end, crank, rods, piston, cam, blueprited, balanced, etc. If that was the case I'd simply shitcan the heads and tbi system and swap it to a carb setup with an 850 holley carb, vortec heads, jet it appropriately, throw in an HEI distributor, and probably get the extra 150 ponies that he didn't get with his **** tbi heads and throttle body.
It's been sitting for 5 years so at a minimum I'd drop the fuel tank, clean it out, put in a new fuel pump! Sure you may have got the truck to start however without addressing those issues your results are going to be mediocre at best!
If possible to give a lot more information on this it will help tremendously with the community trying to offer advice.
Final option would be to just sell it to someone on square body forum since its going to be a nightmare getting the issues sorted without detailed info
