First im very happy with keisler,on installing a five speed in an auto floor pan you will have to modify the tunnel,as far as clearence between tunnel and trans the simple thing is to not use the provied spacer that they send you,as far as the trans interfering with the driveshaft it sounds to me that the pinon angle is way off becouse it bassicly is a top loader and there is no linkage to interfere with anything.Now if he has no gears or cant use one or two of them its probally due to the fact he didnt read the sheet and didnt check and adjust the trans before it went in.As far as there auto set up goes they should have it done shortly,they use the power tour and Matt Delany to test there products and to see if he can tear them up.If you call Keisler and ask for Gray im sure you will get the answers and the info you need.As far as G.V. goes ive never heard a good thing about them.I have also installed five trannys from keisler and havent had a bit of trouble from any of them.The biggest thing when installing an after market trans is to remember that you still have to keep your pinon angle to trans at the factory specs,no more then five degrees,if you dont you will bind the u-joints and drive shaft,yokes.You can use a lazer angel finder and spring shimes to get the correct angle.If you have any more questions about installing a keisler please feel free to ask and i will answer them for you or find the answers.