[dd74]

Dead on, Island. Glenn's correct about the later SC motor being the more friendly engine when it comes to anything other than WOT driving. The lack of throttle response people sometimes complain about with earlier SC motors was later attributed to the intake/cylinder head size, which was later reduced for the '81 through '83 3.0 engine. Thus the SC motor in this form was much more responsive from a lower level on the rev scale. In fact, Bruce Anderson stated in one of his last updates on the '78-'83 SC that the correct intake size for the 3.0 is 34mm and not the larger 36mm. Or is it 38mm?

Now, if you drive WOT more often than in city traffic, I'd definitely do the mods yet with the early heads and intake. That should give you the best of both 3.0 worlds - early and late.