Re: 300 i6 or 302 v8?
If emissions isn't of any concern, I'd stick with the I6, for lower cost of maintenance and possibly better mileage. If you can find a van with a 3.73 rear axle or taller you've got it made as far as fuel economy goes!
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!