looking for a RB20DET box in good condition.
How can I tell if it's of a GTST or an non turbo RB20????
thanks in advance

I'd try looking up the ratios of the R32GTS and GTST because I have a feeling that the NA had wider ratios so a shorter 1st ratio ie 3.59 instead f 3.32 . Then its a matter of selecting 1st gear and counting the number of turns of the input shaft for each full revolution of the output shaft .

thanks for the info
i got 1 reconditioned r32 GTS-T gearbox and it's goin behind the fj as soon as i get the right clutch which im having problems finding one???

cant u just use the standard fj clutch ??

you can use the standard fj clutch.
im using the same RB box behind my fj
any questions let me know.

yeah i know but my fj clutch it on it's way out..
do u know if u still have to cut the tail shaft shorter even after using the fj bell housing on the rb box?

nah the tail shaft fits straight up but one other thing is that u have to use the standard fj bearings. u also have to make the rail holes in the bell housing a little bigger and u also have to shave a little off the inside of the fj bell housing to fit the RB box because the gear of the RB box hits the inside of the FJ bell housing.
i hope u understood that heheheh.

anymore questions let me know.

Thanks heaps
very usefull info there

Nope , get a good machinist to bore the FJ20 bellhousing to take the RB's larger front countershaft bearing . Then fit the RB20 type front bearing cover/clutch bearing carrier support spigot which is machined on the back for the larger bearing .

If you don't do this all you gain strength wise from the RB71 guts is a larger 3-4 syncro hub and later selector mechanism . Hardly worth it because the gear teeth strength is the torque limiter after that front lower bearing . Gear size and ratio wise they are both pretty much the same thing .

so it's better to use the RB bearing
then isn't it easier just to put the RB20 box just behind the fj
and save modifing fj's bell housing?

Not really because the RB bellhousing does not bolt straight up . To get the top bolts right means grinding and welding to suit the FJ block . I know some people just slot the holes but I'm only interested in doing things properly . You didn't find Nissan or Gibson Motor Sports doing things like that .

Honestly boring one hole is easy for a good machinist then it bolts together as the manufacturer intended . I can't remember if we enlarged the selector rod holes , as long as they don't touch the bellhousing its not an issue .

Yeah, I know quite a few who have just slotted their RB boxes and shaved the one of the dowels which made for a direct bolt-on. They havent had any problems to the best of my knowledge. However, disco's option is the best and sets apart the backyard enthusiast and the serious racer.

Im just going to slot, and reweld a plate (ie like an alloy washer) and see how that goes. If I have problems, I still have an FJ housing to use as per disco's protocol.

Hi the rb20det is the same box as the rb25de box hope this helps

the ozzy s3 r31 skyline manuals are a hd. box same as rb20det boxes and can be sometimes had for cheaper. has 2b a genuine s3 box but as s1/2 is the same as a rb20e box, smoother casting with less ribs...

jon.