Learning about trans for LS

Planning to LS swap my NA 944 and reading the (many) opinions and experiences with transmissions, which seam to be the weak link.  I’m planning a realatively stock rebuilt LS1, so sub-400 HP.  I’m not racing the car.  Tires will be comparable to stock—no slicks/wide/etc.  It will live most of its life sub-4k rpm, save for the occasional assertive freeway on-ramp entry—so its a non-raced street car.  I do like low-end pull, so I want my passes to feel effortless: cruise around on the freeway at 1700 rpm then jab the gas to roar around a truck.  Think of driving style as “assertive legal acceleration”—so good pull, but no burnouts, etc.  I worry about torque on the NA trans.

A reman turbo box is just south of $4k, which is pretty expensive, or maybe I’ll get lucky at a junkyard.  Should I just buck up and save my quarters and get the turbo box, or is all this hand-wringing over transmissions for the drag race guys and I’m over-thinking for street driving?

Having built several of these cars for my clients, I've experienced just about every possible transmission issue there is.

First and foremost is that the regular NA transmission is not strong enough to handle even a bone stock LS engine. If driven mildly, some people have had them hold up, but that goes against owning an LS 944. I have had some clients keep the NA trans while looking for an inexpensive turbo trans to install. Most have been brought back with a blown up transmission. The exception to the NA trans is an S2 trans, which is much stronger built.

Second issue with all NA transmissions is gearing. They are geared very low compared to the turbo trans. You find yourself shifting a lot and seldom using first gear. Plus on the highway, you will be turning a lot of rpm at 70 compared to the turbo.

Turbo transmissions are getting harder to find. I usually search on ebay for the most part. There are a few Porsche salvage yards that can be found on the internet.

Another option, but considerably more expensive is the 968 6-speed. Very strong, but a typical used one goes for $3000 plus. Gearing is not ideal, but it's useable. These can also be re-geared to make a great transmission. But again, very expensive.

I have an auto transaxle behind a 450 hp sbc and have had no problems except the flexplate that bolts to torque converter cracked in one spot and i welded some suport to it and its worked flawlessly for over 15 years . If I were doing a manual I would use the turbo or the 944S trans for sure.Not to many has used the auto transaxle or not to much info is out there on it but Im here to say its worked for me very well . Im disabled vet and my clutch leg dont work to good so I tried the automatic with great results .