Q2 on 156 2.5 V6
On GTA the diff is done without removing the gearbox from the car, or splitting it away from the engine. Although it needs doing on a ramp, the process does t expose the clutch do I doubt a huge labour saving would be involved.
As to improvements in handling, if very much depends on how you drive. In a straight line from a rolling start, a limited slip diff makes no difference at all. It does help accelerating from standstill in slippery conditions as you get two wheel drive rather than one wheel wheel spin.
Also, while attacking corners at speed an LSD helps the car follow the intended line as both wheels maintain solid drive as opposed to an open diff where drive goes to the wheel with least resistance, which is the inside wheel. The wheel with most grip, the outside, weight loaded wheel loses drive.
2.5 gearboxes don't have the same reputation for savage destruction under load that the 3.2 cars have, so the advantage over cost would be smaller.
Last edited by Spacecadet; 07-04-13 at 07:17.