Efregoso(92), in case you come back, congratulations are in order for figuring out that you have the LM7 engine, which is a GenIII SBC package. Hopefully you got the ECU and wiring harness with the engine that you bought, and if you can also get the tranny from the Tahoe you'll be in a lot better shape for an easier overall swap. If you didn't get the ECU and harness your costs just went up quite a bit, unless you decide to abandon the computer and build for a carb, which I think is a step backwards (just my opinion).

It would still be great if you can post some pictures of your engine & your Skylark, just for grins, should you choose to continue here. Like you've been told elsewhere, there are several sites dedicated to LS swaps out there.