Ah dang you're right. I was thinking the R154 was the 6'er forgot about the V160.
I got a buddy at work who suddenly came out of the wood work asking me 20 questions when I put my bug Marlin sticker on my box, apparently Marlin is well known in the supra world too for their bullet proofs transmissions.
Of topic, what year Supra?
Marlin is definitely the way to go in regards to R series transmissions. The R154 in the MKIII Supra is pretty much identical to the truck transmissions so the upgraded truck parts do wonders.
Assume you have an R154 Supra transmission you want to build to hold excessive amounts of power. Marlin Crawler makes billet, 100% contact style shift forks that are stronger than the original cast aluminum forks. They contact the shift collar/sleeve for the entire available contact area rather than the OEM style, which contacts only in two points, roughly 12% contact area if I recall. Slam those gears!
Marlin also makes upgraded chromoly thrust washers, which are commonly regarded as the weakest link in the R series transmissions. They also make speed sensor converters for installing the R154 into a newer Supra, if need be.
The R154 was sold in the US installed on 86-92 Supra 7MGTE motor only. The same trans was also found in Japan mounted to the 1JZ-GTE, essentially the exact same transmission but with a different bell housing.
In my case, I'm building my R154 for a 94 Supra turbo (which is currently auto). I got a used R154 that needs a rebuild. Swap the bell housing to the 1JZ-GTE style and you can bolt the R154 to the 93-98 Supra's 2JZ-GTE motor.
The V160 6 speed that is normally in these cars would be my favorite choice, but those transmissions sell for upwards of 6k used. Add in the price of a decent clutch and flywheel and you're well on your way towards 10 grand for a transmission swap.
A Marlin Crawler upgraded R154 is by far and away the best transmission you can have for such a low price. It's no V160, but it will handle just about all the power you can throw at it. The entire swap including every upgraded part, swap parts such as pedals and interior parts, fluids, and labor, will be roughly $3000 by the time it's done.
Another $200 for a longer OD sounds like a sweet deal!