Interesting. For the price, just get an engine and tranny from the boneyard and scrap the LT1. I believe LT1's were built only for vettes and range a number of years, mostly in the 90's, I think. I have no idea as to why anyone would put a high performance V8 like the LT1 into an XJ. You might be able to sell the LT1 off for a good price to a vette owner.