its difficult to say how long it will take you to do the swap. if you're mechanically inclined and have access to a decent set of tools, then it should go pretty smoothly. i pulled two d16a6's and dropped one back into another chassis, and had it running, in 2 days. probably worked 5 hours a day i'd say, 10 or so total. granted i've done this multiple times now. for your first swap, and considering your dropping in a totally different engine, i'd allocate yourself quite a bit more time to get everything done. its the stupid little problems you run into midway that slow you down big time.
Things you'll need/need to do:
-b20b/trans of choice
-obd1 p75 (b18b1) ecu, or p28/p06 chipped with a b20 fuel map
-90-93 teg axles, with 90-93 manual trans intermediate shaft
-ebay,avid,hasport,innovative shift linkages, or shorten a da linkage
-b-series into ef mounts from eBay, avid, hasport, innovative, etc.
-90-93 teg throttle cable
-90-93 teg rear trans bracket, must be from a 5spd
-90-93 teg driver side engine post mount (part that bolts to the block), 94+ b-series mount has different bolt pattern/layout and will not line up with the aftermarket engine mounts.
-you will need dx,ex, or si hubs if you haven't already switched out the stock std hubs. std hubs will not work with the teg axles.
-then pull out the dust rings from inside your hubs. this allows more room for the axle to move and prevents the constant velocity joints from binding on lowered vehicles.
- since you have an obd1 b7 currently i'm going to assume you've already moved/extended the coolant fan switch from the back of the block over to the thermostat housing.
-lastly, you will need to make a dent on the lower driverside frame rail to allow for alternator pully clearance.