S13 Silvia - Rear Subframe Swap Question

[Pixel6]

So question...

I have a 91 Silvia with the super HICAS rear subframe. I bought the lockout bar, but just found a pretty good deal on a standard USDM S13 subframe.

So before I clean it all up, put on all new Energy Suspension bushings, and the ISR suspension kit, I need to know a few things...

Are the subframe mounts on my Silvia all in the same position for both subframes??

The USDM one came with an open differential. Will my stock LSD that’s on the super HICAS bolt straight up?

If so I’ll probably weld the open diff to lock it, and have the ability to swap em out as needed.

So yea, the big question I have before I begin, is if it’s just a straight swap and if all the bolt holes line up on the main subframe mounts.

Thanks.

[ANDY black s13]

the sub frames are same mounting points,the diffs will swap between the two sub frames
the only difference afaik is in rear half propshaft lengths open diff longer lsd shorter

[Pixel6]

Nice. I’ll see if I can source a half prop for the open one then. Or maybe have a shim made as I would need to lengthen my oem one to accommodate the open diff.

[ANDY black s13]

if you go with the shim option it needs to be well made and locate same as the prop flange
imo go with swapping rear ends of the prop to avoid diff bolts coming loose problems
the only possible is prop shaft imbalance and vibration,flip rear half 180 degrees

[Pixel6]

It’s coming along.

Energy suspension bushings all around. Bunch of ISR adjustable bits. Made a mistake and cut out the collars on the main subframe bushings, so had to order new whiteline bushings, burn out the bushings that came with it, and press in the collar to add the ER bushings again.

Went ahead and got new wheel bearings, brake pads, rotors, sway bar links, axles, eccentric bolt lock-out bolts.

Rebuilding the calipers today, and welding the open diff that came with the setup.

Still need to source steel and rubber brake lines, then she’ll be ready to go on! (Although I’ll probably change the fluid use the LSD that’s on the car now, and use the LSD)

But yea, all painted and looking good!