Stock manual sc300 drivetrain for GTE swap?
 

Hey guys, I was just wondering if you could use the stock w58, driveshaft, and diff. if you do a 2jz-gte swap?
I know its not recommended due to it being a "weak" transmission but I've read that they can be used for applications up to 400HP.
I will not be exceeding 350HP anytime soon so I think I'm okay for now in that category. I know you have to upgrade the clutch, maybe flywheel, but I wanted more clarity on this. I couldn't find much information.

Approaching 350rwhp , you are on borrowed times with the W58. And depending on how you shift / take off or use your car , even less.

Just for casual driving it should be fine right? I can use the same driveshaft and differential still correct? I don't plan on doing mad burnouts, "skids", racing or anything yet, not until I can properly drive the car and afford a R154. I would like to use the w58 until I can attain a sc400 for a 5speed swap on it and the do the R154 on the sc300 :3

^^ Gerrb is telling you the truth, OneSC. Yes, people have used W58's in their turbo JZ SC's but it really, really comes down to the condition and wear of the W58, how carefully it is driven and shifted and the conditions you put it through. People's experiences vary quite a bit with boost against W58's. The unquestionable constant, however, is that it is only a matter of time before the W58 breaks when used against a boosted engine. In some cases you do not even need to load the gears aggressively or shift aggressively to cause a failure. It totally depends on the accumulated wear on the W58 from new and how it is used.

Toyota never designed it for JZ boost applications or even 7M boost applications (since earlier W58 designs date back to at least 1982; the SC300 W58 version was revised for 1992+).

Using that same transmission with a stock 250hp SC400 is fine. The power and torque delivery is still very linear in that case and not all that much higher than an NA 2JZ. Turbo power delivery is not linear and the gears in the W58 were not designed to handle that long term.

If this is a frequently driven car and you can't park it for a while to work on it you could also focus on your transmission upgrade before you swap a boosted engine in.

An R154 (especially from a Soarer) is going to be the closest to a factory-like bolt-in solution. It will handle the mere 350whp you plan to throw at it for years and years without any issues. Be sure to look up the differences between MKIII Supra R154's which require some conversion and JDM tripod R154's from later model Soarers, Chasers, Mark II's, Verossas, etc. which require little conversion to fit into the car.

Alternatively there is the AR-5 transmission (very similar to the R154 with a conversion kit available) and the CD009 350Z 6-speed (conversions available for this also). And though it is pricey the Grannas Tremec Magnum 6-speed is another option. The Supra V160/161 isn't a reasonable option any longer.

The factory W58 is a great 5-speed transmission that NA 2JZ-GE's and 1UZ-FE SC400's can use. It's just not suitable for boost applications sorry to say. As Gerrb says... boosting with a W58 puts the gearbox on indeterminate borrowed time depending on how you use it.

Thanks for your input! I probably wont do the swap this year then. I was planning on having it done by the end of the year so that when 2018 comes around, all Ill need to do is upgrade the transmission. And by no means will this be a daily driven car, I have a LTZ cruze for that nonsense haha. Its just a dream car i've always wanted and will be taken to meets and whatnot. It'll be driven maybe twice a month? at most due to next year being a workload year.
But as far as the question goes, I could bolt up the motor to the transmission, no alterations needed?
Anyways thanks again, ill ask around again when it's time if I haven't found a reasonable solution.