I am almost ready to install a late TR4 (with the thicker bellhousing) A-type o/d tranny in my 59 TR3A. Planning on getting the extra pieces from Quantum- switch, right angle speedo drive, relay, harnesses, etc. Other than longer bolts for the bellhousing what unknowns am I looking at? Will I need to adjust driveshaft length or is this unit a "bolt in'? Looking forward to having the Laycock unit but don't want any surprises.