Does the 700r4 have a machanical speedo and vss?

[beamn7]

700's had a cable up until about 90-91. After that point they had a speed sensor that installed into the trans in what looks just like a speedo gear adapter but had a sensor rather than a gear. Once they became the 4L60E in 92 they all had VSS's on the trans. The 2 wire plug you mention most likely is for the torque converter clutch if it is a plug on the drivers side of the trans that goes straight up and down and has room for 4 wires in the connector. Beginning in the early 80's most of our trucks did have speed sensors though and as previously mentioned, they are behind the speedometer. You should be able to pick up your input off of that....
Are you planning on keeping the truck registered here in CA? If so, you may want to do some further research as I too have been looking to do a TBI install but nobody has a system as of yet that is C.A.R.B. certified....
Howell Fuel Injection out of Howell, MI is currently in process of getting an Executive Order # from CARB for one of their kits though....
Hate to see you spend the time and money and then not be able to get it smogged / registered....