Did GM put 241 heads on '00' cars? Reserch shows that I should of had 853 castings instead of 241. 241 should of started in '01' but I have a '00' with 241's. I take it these two castings have the same specs.

 

No....the 241's actually flow a bit better than the 853's stock...don't ask me why....they spec out the same in GM's book....but the stock 99's that had the 843's were always a bit slower than 00's and 01's w/the 241 castings....you probably have a car built towards the end of the 00' model year after they had quite casting the 853's and they started using the 241's. Bee happy....they're the most up to date design next to the LS6 (243) castings.