Quoting HoosierGvr4:
Well, currently sitting in the garage is a built 6 bolt with a gt3071 turbo 1600cc injectors ect ect.. waiting to be dropped in. Its mostly going to be an after work/week cruising vehicle with occasional track time once or twice a month. I've been known to be fairly abusive on my vehicles so Im hesitant to run the 3 bolt set up, but I've also seen a decent amount of people get away with using them so Im trying get a consensus of how good they actually are.
3bolt rears are halfway decent, and you can get away with a fair amount of abuse on them but it's always a gamble. I've had the OEM non-lsd 3bolt in my car for over a year and lord-knows-how-many launches without issue, BUT, it is an open diff so I really dont have to worry about snapping an axle(since the wheel with the least amount of traction is ALWAYS going to spin.....and spin it does).
On a moderately modified car, under 300hp you should be fine with a 3bolt LSD, for a while. Pass that marker though, and every launch is a gamble on the life of your axles. The actual rear end isnt the weak link, it's the axles.
Honestly, based on your plans of a built motor and bigger turbo, I'd stay away from the 3bolt. Just be patient, and get a 4bolt.
-Jake