some cars, have gears on the end and you had to find the esact tooth, out of up to maybe 16 or motre teeth on the shaft. These Toyota distributors have a shaft with a slot. Worse thing that could happen if at all is be 180 degrees off... but if you mark the exact postions, it's almost fool proof. I like top place some engine oil on the O-ring before I slide the shaft back into the head ont he end of the camshaft. just puts some on your finger, or on a papaer towel and apply the oil to the o-ring on the disctrib shaft before putting it on.
The idiots at the factory, who put the coils in the dictributor had the wirers twisted on the coil wires holders, so the white wire was not in its slotted holder. I had to undue one wire and place it under the other and put it back on and tighten the screw,, so, take a look at everything before you put it on the car..
also, make sure you take the post off the battery terminal so you don't have any live fire coming tot he distributor whyile you r&r it.
