Zack,
I had the same/similar motor in my 88 suburban which had the TBI with the 5.7l motor. What I did that saw huge gains was change the intake manifold and bolt on a pair of headers.
For the intake I went with Edelbrock and I chose Thorley for headers. In addition to these changes they do make a chip for your truck as well. If you decide on headers make sure that you pick a set that have thick flanges that won't warp/leak. PM me if you have any questions.
Also, Holley has an aftermarket injector that they make which you may want to look at.