First, find out what "extensive modifications" means. I don't know that much about Rogers other than what I've heard which has all been very good.
Find out who did the "extensive modifications" as well. There's not a lot of people I wouldn't trust doing "extensive modifcations" to an LT5 engine.
If you get the information and you get serious about it, let me know. Try and get me the vin number and I can check around and possibly find someone down there to check it out for you.