454 Medium Duty V-8

[Bob B.]

I don't think the L21's were tall deck, though all the 8.1's were. Of course, the '79-'80 would have been a Mark IV, the '99 a Mark VI.

Never sure why the 454 was released as a medium duty engine for '79-'80. H.P./torque was only slightly better than the 427, fuel economy was about the same. I am thinking it was either because of emissions or GM was moving to eliminate the 427. The 427 was not available in California certain years in the early 80's.