Pretty much the only options you have are buying the Advance Adapters VSS kit that goes on the trans output shaft $244 that involves drilling into the stock tail housing on the trans.
Or you can sell your SYE and buy the JB conversions one that uses a GM VSS in the tailhousing of the 231j $340+ depending on yoke choice
There was a guy on Pirate in the 5.3 swap thread that did something similar to the AA kit using parts he had on hand and machining the adapter for the tailhousing, but that requires quite a bit more work than either of the above options. I was originally going to be running a 231/D300 doubler on mine and was planning on using the AA kit as that was the easiest and the GM computer has no provision for 2 low ranges. I ended up with the 241c for now as it was the cheapest/easiest to use for now until I upgrade to an aftermarket case in the future.