Atlas 4.3 is 110# dry. It comes with a twin stick mechanical shifter but you can upgrade to a twin stick cable shifter for $70. This will make shifter mounting much easier.
I love my Atlas but they get expensive. I have the 4.3(no speedo), 32 spline outputs, e-brake, and 1350 cv flanges. It cost me more than I care to remember without digging up the receipt. I am running it behind a th400 with the short out put shaft which is found on the 400/203 combo. If I had it to do again, I would have used a longer output in the transmission because my front shaft angles suck with a 4* clock on the t-case due to how short it is. I had to change it to an 8* clock just so my shaft wouldn't bind. My overall length from bellhousing to output flange is 35". I still have a flat belly with an 8* clock on it. Any more and the t-case would hang down a little bit. I also had to cut the hell out of my floor to get it to fit at that degree. As for gearing options, I built a th400 with a full/manual valve body so I can start out in any gear. Here is a run down of my gear choices (t-case output values):
10.7
6.4
4.3
2.48
1.48
1.00
The doubler will weight near 250#'s all said and done. You really don't have to many more gear choices due to the cases both having close to the same ratio. I figured them all up one time and there just weren't that many more options that what I have now. I also plan to add a Klune-V in front of my Atlas in the future. If gear ratios are what you want, go with a WMS 3.0 NP203 and NP205. That will give you lots of choices.
