46RE on boost you'd wanna talk to Greg (Redtruck-VA) over on HTC; he's here occasionally but usually over there. Chrisp2493 put one in his 2003 coupled with a console install; you can search for his posts and see it. Let's talk pros and cons of both trannies. I'm ultimately going with a ZF swap simply because I want the two OD gears like I have already. I'm just tired of going through trannies lol. I figure if there's a guy in Canadia running around in an 04 QC with a 6.1 based 392 with an 8HP70 then my short term plans will work just fine with it. So:
46RE pros
- proven swap
- can be made pretty damn strong
- can use the factory shifter if so desired
- relatively inexpensive since the 46RE was available in the 3rd gen Ram (albeit not one as new as yours or in a CAN bus vehicle)
- can be manually shifted
46RE cons
- literally only a three speed with a single OD....if you don't go far then this isn't a big deal
- technologically speaking is pretty old
8HP70 pros
- 6 ******* gears plus 2 overdrive gears, amazing gear ratio split with an unholy first gear
- unholy first gear negates need for steeper final drive ratios (this is why Hellcat auto cars come with 2.62's)
- plenty strong, lives behind 485hp 392's all day, even ones with low boost
- can be made even stouter or replaced fairly easily with an 8HP90/95
8HP70 cons
- not exactly cheap to buy a trans outright
- the required adapter harness is a GRAND by itself (but is amazingly simple to hook up, even easier in a CAN bus vehicle. He's almost got it plug and play by now)
- there are no factory parts to put it in anything prior to a 4th gen Ram
- requires one of the available electronic shifters; this is a ***** for 3rd gens because it's either console type or dial, neither which is a quick and easy fix (though he is working on that with his 2010 5.7 Ram test mule)
- no provision for a slip yoke; 4x4's have this easier because you just bolt the t-case on and go. 2wd's have to use a slip driveshaft
- internal software (ZF TCM is inside the trans as part of the valve body, which is why the harness has an OBD port in it) isn't directly compatible with anything prior to a 4th gen at the moment