5.3 4l60e LS to TBI swap help!

Hi everyone! I'm very new to this thread so excuse me if I posted this in the wrong area or anything! I have a 1990 c1500 with the 5.7 TBI. I'm in need of some help with an engine swap I'm thinking of doing soon. My old TBI with the 700r4 has 170,000 miles on it and is getting terrible gas mileage, and the power output is something to laugh at I found a 2001 Silverado with a 5.3 and a 4l60e with 116k on the clock. Wiring harness and everything, I can get both for $1150. Seems like a very good deal. I know that I'll need a new fuel pump to supply the higher PSI the 5.3 requires, and I also know I'll need engine mount adapters. What I'm mostly concerned about is the wiring. How do I have the computer off of the 5.3 "talk" to the stock TBI computer to show my speedometer, oil pressure ect. gauges? I've searched all over the internet and I have yet to find anything about putting an LS into something that runs off of the TBI. And any other parts I'm forgetting about that I might need? Any help would be greatly appreciated!

My swap was in a 96 which is a little different as far as controlling the trans is concerned so this may not be accurate for your application "but" there will be a wire coming out of the LS pcm that you will splice into a wire coming out of your factory pcm for the speedo to receive the signal. Oil pressure and coolant temp use your factory sending units and wiring you just have to buy adapters to make them fit in the ls engine (different thread pitches)