it all depends on the option contents, the newer ones SHOULD be a bit heavier, the more electronic options you have the heavier, for examply a fruise control option ads like 3 pounds, power windos 12 pounds, AUTO tranny verse standard like 100 lbs. etc, and the WS6 package was more or less a suspension package, so most WS6 ta's had 305-325 depending on the ram air kit on it, they had a limited pro SLP package that was called the firehawk and I think it had an underated 385HP.