Well, since nobody seems to have any (other) thoughts I guess I'll just think out loud here...
Based on some of the discussion going on over
here, the 3.9L bellhousing from a 94-99 Dakota (pictured above) is the best available option for mounting one of these Aisin transmissions to a 5.7 hemi. That 3.9L bellhousing however comes with some caveats, it requires an 11"/143-tooth flywheel. If you're bolting it to a standard smallblock you can just transfer over the V6 flywheel, however in my case, Mopar hooked me up and changed out crank bolt patterns. This means I have to find an 11"/143-tooth 5.7/6.1 hemi flywheel. Now, they are available, although expensive and aftermarket. I was trying to avoid aftermarket parts simply due to maintenance parts availability.
So... the MA5 is a little steep in the first gear department at 3.753:1. Certainly a lot of gear in comparison to nearly any aftermarket trans or factory available option. This affords me the ability to run a very conservative gear and keep my highway rpm's more than reasonable. Based on the recommendations of a multitude of sites online, the range of 9-11 for a starting line ratio (first gear x rear gear) is a good middle ground for a street car.
With a 2.93 rear gear I will be at 10.996, or 11 for simplicity's sake. Already on the high end of that range, my shorter tires, 315/35/R17's, are only 25.7" tall, effectively increasing my launch ratio. A 2.93 rear gear puts me just a hair under 2000 rpm's cruising at 70 mph in 5th.
With a 2.76 rear gear I will be at 10.36, more middle groundish, cruising at 70 around 1850 rpm.
3.23's seem a little too steep... My only concern is that this car will be a street car and see some parking lot autocross or time trials style races, a little quarter mile and stoplight to stoplight drags. Maybe even some standing mile or 1/2 mile, I think I'd really like to try that. Does 2.93 seem like a good compromise to those of you drive stick cars out there? Will it launch comfortably on the street and aggressively at the track, yet first gear won't be a waste and barely make it through a stop light? Would 2.76's be too tall? I'd also like to have a little room to go with some slightly taller tires in the rear if I decided to. I can't see going taller than 28" for what I'm trying to do.
In connection to all of that, I know steel flywheels are pretty much the rule for the street but would my high SLR and relatively low weight early A(shooting for 3500 lbs MAX with me in it, hopefully much less, just trying to be conservative) allow for the use of an 11" aluminum flywheel? I think it could be beneficial in the autocross and time trials situations. To be honest, this will be my first vehicle with a stick, I am thoroughly
excited about it.
