in response to pgackerman what modern 4-banger producing 200 +hp and a lot less weight more room in the engine bay and better mileage would you suggest and how hard would the swap be?
The largest non-boosted Ecotec 4 cylinder (2.4 L) makes almost 180 HP in stock form. (30-40 HP more than a stock V6)
With a good header and intake, people are "claiming" ~200 hp.
Boosted, they're making in excess of 300. Waaay in excess.
Swaps are not really simple. Require a bunch of ECM "tweaking" or an (expensive) aftermarket ECM.
There are people selling mounting brackets, however.