I know that you can swap ECMs to the ECM from a LS engine. Its called the 411 or 0411 swap. It takes repining the connector for the OE ECM. There is a ton of info on LS swaps on you tube. If you want to get in touch with someone who has done the swap, You should try https://www.gmt400.com
That forum, is just for OBS 1988 to 1998 body style trucks, Burbs, Tahoes. There is a member there that has done the swap. You will have to join to post of course, but it is also a grate forum. There are several members with LS swapped trucks also.

 

OH wate, you have a 95. That is the odd ball year. TBI but looks like a 96 up inside, almost. You will need the ECM for the 6.0 or the ECM from a LS engine, with the connectors, unless you carb the engine. Anyway, you really need to post this on https://www.gmt400.com I know the swap is a can do.

 

Here are a few threads on LS swaps on www.gmt400.com
https://www.gmt400.com/threads/ls-swap-1999-c3500-single-cab-lb.42501/
https://www.gmt400.com/threads/6-0-into-2000-k2500.39892/