Well, you aren't wrong, that was really my biggest concern. My math says RPMs will be a hair over 2k at 60, so I'm thinking having the stall speed below that would be a good thing. Less heat generated, etc? It's a lockup T/C, but I'll have to dial in the manual control of it (no computer).
Just a couple of things I noted when I put one behind my 5.9
First gear is a lower ratio in the A500, than a 904 and the stall is probably going to be in the 15-1600 range behind the 318.
That will give a 318 some decent jump off the line.
If the A500 you plan on using is a pre 1996 I can show you how to build and automatic shifting setup for OD and lockup by using the governor output pressure and adjustable pressure switches.
Mine shifts into OD at 60mph and lockup at 70 completely automatic, or I can shut off either or both manually if I wish.
Adjustable switches means I can set the speeds I want OD and/or lockup to come on and go off at.
Hiway speed limits around here are 45-65 and 75, so 1-2-3 only in the 45 zones, OD at 60 in the 65 zones, and lockup at 70 in the 75 zones.
The 5mph difference on each is to minimize hunting back and forth between gears.
I generally do about 80-85 in the 75 zones at about 2,100rpms
That .67:1 OD adds in the neighborhood of 35-40% increase in fuel economy as well.
I was getting around 17mpg on the hiway with my stock 318, and I get right at 25mpg on the hiway now with a mild built 5.9 Magnum and the OD.
Also these transmissions cool really well in OD with lockup engaged because of no converter slip or planetary gears spinning in the main case.
In stock form they are a little mushy just like the older stock TF transmissions, so I would highly recommend a TF2 Transgo kit be installed.
