I've got three 454 trucks now, a '76, an '81, and a '98. I'd like to know the horsepower/torque of each engine, generation, and what is different between the three. The reason I am asking is because my '81 has a lot more pep than my '76. The Vortec 454 is obvious on the changes, and am really only looking for the power numbers on that engine. '76 '81 '98 My main thing is wanting to know what was changed on my '81 454 from the '76, as it is so much peppier and both have identical Th400's and 4.10's.