If your SC did not originally come with a tripod style shifter....you will need to take out the tunnel (drill out spot welds and pound out tunnel) and replace it with the Supra 6spd tunnel....

I just recently did this to my 92 SC to fit the tripod r154 in my car.....Please look at my build thread if you want to see how to do it

 

no that is not correct you missed it twice now. if you have a 95-97 5 speed sc300 then swap in a r154 with a remote shift or a v160 (only comes in remote shift) those would be a direct swap in no cutting needed nada just bolt it in and go.

the 95-97 sc300 manual tunnel is almost exactly the same thing as the v160 supra tunnel, they both use REMOTE SHIFTERS aka tripod shifters.
The later model R154 off a soarer or 1jzgte uses the exact same REMOTE SHIFTER also.

if you have a 95-97 5 speed sc300 then swap in a mk3 r154 with the swan neck or an early model soarer r154 with the swan neck, then you would be doing lots of cutting as the hole sits more forward. this also applies to a w58 with a swan neck its in the same place as a r154 with the swan neck.

so there are 3 different transmissions, but there are only 2 places where the shifters come out.
by the radio on the older swan neck, and in the center of the shifter bezel for the remote shift.

if you have an auto car you have to cut, but if you have a manual car originally, its easier to get the right transmission.

 

Ah ok, thank you for clarifying

 

Just read through the whole thread and I'm in a similar situation as the OP. I have a 97 auto SC3 but have an early SC3 W58 trans (92-94) that I'm going to be putting in. Do I need the swan neck shifter after I cut the trans tunnel or the shifter isn't necessary?

 

if you have an early w58 trans you will need the swan neck shifter it came with to get it in the middle of the console, and since you are auto, you will be making a larger hole up front of your existing hole.

 

My trans has the stock shifter so I'm assuming it has the swan shifter. I came across a parts list from another thread on what's needed to do a w58 swap and it listed the swan neck shifter for 175$ on there so I was confused for a sec

 

early sc's 92-94 came with the w58 with the swan neck shifter and is the stock shifter that gets the name cause it has a little bend in it, its the same as the r154 swan neck used in soarers.
This was the easiest solution for toyota to get the shifter further back for the SC/Soarer/mk4 Supra without designing a whole new housing (the housing was a bit longer than the previous ones though).

you have to use this bent shifter to fit the right spot in a mk4/SC/Soarer as once the trans is installed you will see the shifter housing lines up under where the ashtray on your console is more or less, so to get it in the middle of the trim behind that there is a bent shifter and this puts your shifter at an angle towards the rear of the car, most mk3 supras were like this anyways so it was not unreasonable at the time.

the supra mk4 w58 got the "remote shift" like the SC and Soarer did around 95, which extended the shifter mexhanism to sit much further back basically directly under the shifter trim, so shifters on these cars stand straight up and down perfectly when in neutral, they are not tilted like previous generations.

so you have to run the swan neck or you have to get the shifter lever and housing extended (think mk3 r154 extension there are pics online) and then you can use a straighter shifter as the housing will sit more rearward. If you have a stock w58 with the stock bent shifter just install it as is, but you will be making a new hole further up by the radio console.

early w58 "swan neck" shifter hole is the closest to the stereo trim, the late w58 "remote shift" hole is exactly in the middle of the shifter trim, and the auto trans shifter hole is between the late w58 and the cup holder.

So you can see depending on which shifter you use it means where you need to cut the hole.

so a remote shift v160, w58, and r154 all fit perfectly in the late stock w58 cars (95-97 SC's and all manual mk4 supras) with no cutting.
the swan neck shift SC300 w58 and Soarer r154 fit perfectly in the early stock w58 cars (92-94 manual SC's). (do note this might not fit perfectly if the w58 or r154 is from a mk3 as the housings are a touch shorter).

If you are a stock auto you will be cutting for both setups, but the remote shift will be closer to where the hole is originally.

 

Soooooo, while were on the subject, can I ask which tunnel to use for the 350z trans or is this a whole new can of worms..?

 

the 350z with the normal shortening like 34" wants to come out of the cup holder or between that and the 95 spot.
since it sits furthest back and the shifter housing is sort of tall the 95+ tunnel would be the best bet (its stlightly taller to clear the tripod type shifter housings), but you would still have to make a hole further back basically where the auto hole is around.

with the 240sx short shifter mod I had posted to get it down to like 32" it would still come out of my 95 tunnel hole, but 2 inches behind perfect center where it is now.
So maybe a small notch would be needed then towards the auto hole, this is the closest tunnel to it fitting normally if you reduce the length to 32"

the 92-94 tunnel has the hole way off for the 350z trans, not even close. but you could probably close the hole up and drill a new one further back in the right spot, but there is that issue I mentioned above about the newer tunnels being taller I think they have a hump for the tripod stuff to fit better, which is why people installing tripod trans into 92-94 normally change out the tunnel (or bash it out till it clears with a BFH).
no idea if the 350z trans will fit the old style tunnel without bashing, couldn't tell you but if I had to choose a tunnel to start with for that trans it would be the 95+ OR v160 tunnel which are more or less the same thing.