If you have a T5 (separate bellhousing), you are good, other than having to do the same mods that everyone else does when using an S-10 T-5 such as cutting off the pilot section, extending the splines and shortening the input bearing retainer. There is NO difference between the 2.5 and 2.8 T5 other than gear ratios on some early years (82 & 83). The '90 T5 will have electronic speedo. If you have a S-10 with the Getrag transmission, then you have a 1-piece boat anchor. These are indeed light duty transmissions that only found their way behind 2.2 liter and some 2.5 liter engines.
The 4.3 V6 in the S-10 only got the New Venture transmission with the integral bellhousing.
You will find the van suspension a bit wider than truck suspensions. other than that, it sounds like you have a start of a plan. Good Luck
