Theoretically you can use the one to build, but you will find out when you get in there.
I had a VSS one that I tore down to build, but it had some issues which led me to tear down the mechanical speedo one, and it was in better shape. So I used it and changed the tail to VSS.
I found a pump and chain on eBay for a decent price since I hadn't gotten one with the bearing and seal kit that I had picked up from ORD. I don't remember the name of the place on eBay though.
I don't know what pointers I may have right now, but make sure that you pay attention when you put the rear bearing housing on over the pump. These cases are pretty easy to build, I use an old GM manual, but I think that others will do..??
When you bench test it, you have to have the rear bearing and snap rings on the correct spot to have no noises.
I just did an input gear swap on one that had an SYE kit. It had the rear snap ring in the wrong groove. This held the shaft wrong and pushed the seal out of the pump. (I guess there's a tip....lol! )
Make sure that you get all the contaminants cleaned out from the area between the planetary ring and the front of the case. There can be a decent amount since the planteries turn all of the time and there isn't a direct drain from that point.
Oh , and don't use too much silicone on anything, but watch the input bearing retainer. I found that same case had the oil feed hole for the input bearing plugged with silicone.
Watch which direction the shift collar points on the main shaft, of course...
