Hey guys. Thanks for your responses. The engine I looked at has 378 hp and 399 tq. That's just a baseline really though. I'm just trying to get research done. I would like to use a gearvendor unit, simply to make the car more drivable. My end goal is drive to the track, run good times, and drive home. Also use it as a fun weekend cruiser. Thanks for all your help guys. This forum is easily the most polite of any I've ever used. I appreciate it.
My car has a 904 behind a Vortech-supercharged (approx. 500 hp) 360 in a 3,300-pound car and has never given me a minute's trouble despite a LOT of drag racing activity. It's tough.... so far.
The downside of that transmission is, no overdrive.
Mopar overdrives (A500 and A518s) are difficult to retrofit to A-bodies because of the physical size of the tailshaft-mounted overdrive unit. They require a fair amount of floorpan surgery and a modification of the transmisssion-mounting crosssmember in A bodies, but, some feel it's worth the trouble. I don't know about B-Bodies... maybe no such travail is necessary... but, it probably is...
The last time I checked, Gear Vendor units were deliberately geared to split the difference betwen 2nd and 3rd gear (.20:1) and aren't really that effective as an overdrive. They may have other ratio options, by now... but, I doubt it...
The A500 and A518 Mopar units (and, I believe, the 200 4-R) are
true overdrives and have a 4th gear effective overdriven ratio of .39:1... offering a significant drop in highway rpms. For instance, a Gear Vendor unit would drop your highway rpm from 3,000 to 2,400 at cruise, while a 518 would drop it from 3,000 to 1,830...
However, it's so easy and relatively quick to change a third-member in an 8.75" rear, so, I just keep a 2.76:1 unit around, and put it in if I'm looking at a considerable amount of highway driving, and change back to the 4.10 for the strip. No big deal...
You pays your money and you takes your choice.... :study:
Hope this helps...