the tailshafts are not identical between the electric and mechanical S10 trannys. The way the gear is held onto the shaft is different.
The adapters to go from electric to mechanical are very expensive, around $300 I'm told. It would be cheaper to get another tranny...
I would sugest that since you are having a shop do the work, offer to trade the shop even up, your tranny for a mech. version...
Like I had said before, look at the speedo sender before getting the tranny. If it has an electrical type connection, its the wrong one. All the mechcanical senders are screw together, just like your stock one.
