If you haven't looked into it yet, check out www.dynamicefi.com. Far as I'm concerned it's the setup to use with TBI and OBDI in general - if you want to stay with factory electronics. There are other options out there that are 'easier' to tune - like the self-tuning setups out by FAST, MSD, Holley, etc. - but far as I'm concerned those are no fun, unless you just want something you can slap on and go without tinkering with... I like to tinker. The only 'drawback' you have is the fact you have a '95... '93 and later trucks have the 'E' trans (electronically controlled) which the EBL doesn't run - but it's still possible with a 2nd ECM, essentially dedicating one ECM to the engine and one to the trans - that is unless you have a 5-speed, in which case you're golden to use the EBL. Unless you have a lot of overlap on your cam causing a rumpitty rump idle, I wouldn't worry too much about tuning. The EBL more or less tunes itself as far as fuel requirements go, and your fuel setup is capable of the engine you built (with the right injector/pressure combo TBI can supply 500hp). I would say go for the 400 block and just get the Vortecs drilled for steam holes, and go with a cam between 210-220º on the intake, plus another 3-7º for exhaust.