Here are some estimated weight savings with aluminum parts:
Intake 25
Headers 25
Water pump housing 15
Heads (pair) 50
Total for above: 115 lbs.
Source:
http://www.bigblockdart.com/techpages/weight.shtmlWhich engine best suits your needs really depends on what is most important to you. All else equal, the 440 will be cheaper to build but require more upkeep. Since you already have a 440, that makes it much cheaper on initial costs. Stock, the 5.7 VVT probably has slightly more low end torque than the 6.1. Low end torque is good for a modern small block but is not at all comparable to a slightly warmed over 440, let alone a stroked 440. The Gen III hemi is pretty much dead below 3000 rpm unless you have forced induction. However, once you get the rpms up they make good power; the tach needle visibly speeds up when you cross 3500 and 4000 rpm and runs great from there to redline.
The Gen III is going to be much smoother. That is both good and bad. The downside is you won't have the cam lope and rumble at idle of a 440 with headers & cam. But if you are driving any distance, don't underestimate the much better fuel economy on the Gen III. If you are getting 6 - 8 mpg with a stroked 440, then 18 gal. tank x 8 = 144 miles from top off to walking. Allow a 30 mile reserve and you have to fill up every 114 miles, and that is without any aggressive driving. My main concern here is not so much the $$$ for gas but the lack of range. If you have an aggressive cam and get 6 mpg and leave a 30 mile reserve in the tank, you are 18 * 6 = 108 miles to empty, so 78 miles between fillups with a 30 mile reserve.
The lighter weight of the Gen III is another obvious plus.
