I am in the process of LS swapping my 87 GTA. I bought the car as a roller but it was originally a 305/t5 car. I plan on dropping in a stock lq4 and T45 transmission. Mainly will just be a cruiser.

I know t56 is the go-to but I don't have one. I do have a T45 (1381-000-011) from a 2000 mustang and I came across a guy who makes t45 to LS adapters.

I haven't mocked anything up yet but was hoping someone else has maybe done this before. The trans mount pad doesn't look too far off from a t56 and from what I can tell the shifter location looks close to the T5

I will need to figure out the crossmember and then a driveshaft. The trans to engine side should hopefully be covered.

Any tips on making this setup work would be appreciated!

 

Theres someone on this board who did it. The shifter was up by the ashtray. An adaptor was used to get it in the stock spot. The DS/yoke is pretty easy. You'll need a 10 spline clutch disk to work w the GM flywheel. It should be pretty easy. A custom x-member is easy and mount your torque arm to that. Speedo will need to get worked out.

 

that's good to know the stuff i'm stressing on might be simple and I'm just overthinking it.

I think I know the thread you are referring to, I think that guy used an AR5 and a remote shifter.

The T45 shifter location should be about 27" from the face of the bellhousing and the T5 is 27.5"
https://core-shifters.com/pages/shifter-distances

I also need to figure out a hydraulic slave, the mustang used a clutch cable. There's a conversion kit out there I will just need to see what everything looks like once it's mocked up in the car.

 

Good point, yeah different trans. You should be good w that.

A slave cyl mounted on the front bearing retainer would work really well. You can likely find a a stock(ish) master to actuate it.

 

I'll keep you posted on what I come up with.

I've been scouring the internet looking at different transmission dimensions and found that the mounting pad on a TH400 is 24" from face of bellhousing, 4L80 is 26", the T45 looks like 24.5" plus a 1/2" adapter plate so 25". TH400 crossmembers might be a good place to start and modify without reinventing the wheel