85 lwb turbo 5.3 build

[85burb]

Ok this is a new one for me. I did a 6.0 in my burb but it was carbed then aftermarket efi. This one will be factory efi with turbo. Never had or built a turbo motor before. So i will be needing some help. I plan to get a 5.3 and change the ring gap and maybe a cam and head studs. But no heads or crank/rods. Would like 500 hp to the ground. I have looked on the ls1tech site and the lowest on there i can find with a 5.3 and turbo is 550. Should not be too hard to get that power mostly stock. We went around and around about what to do with this truck and it has been for sale for a while with no real takers. So i finally talked wife into keeping it. YAY. Now the fun starts. It will be a slow build as i dont even have the motor yet. I have my eye on just chevy trucks.com they have a ebay store that sells stand alone motors. All pullouts and come with a current performance harness and ecm. I have seen 5.3 with stand alone for under 1000 bucks. Has anyone used them or that harness? Not sure what size turbo yet. I have tons of resurch to do on that. Should be a fun swap. So here are some pics of the truck. Any advice will be appreciated.