I would put a NV3500 behind the engine over a T5 if you want to stay stick. These came out of the S-10's with the 4.3 V6 and will bolt up to the 292. If you want an Automatic, a 700R4 is the way to go, you just need to add another brake light switch and a vacuum switch to get the OD to work properly.
Get a guild sheet on the engine to see if they built it stock, or bumped up the compression or gave it a better cam, etc. The 292 has a long stroke for lots of torque, however is not a high RPM engine. Stock HP will vary from year to year, however you can get about 250 out of them with out much effort.
Good buy on that. I myself would do the 5-window, then again, its your project.
