I was at some high rpms too with 3.73's. 3400 rpm at 60mph is bad on the gas, but 2050 rpm at 60mph is more like it! $3k is WAY TOO MUCH! Go to phoenix trans that 67ss was talking about if you want to get one already done...$1300 is not bad. I pulled mine from a Monte Carlo. GM produced the 200 from 1982 to 1990. These transmissions were installed in numerious vehicles like: Buick Electra, LeSabre, Regal, Grand National, Chevy Monte Carlo, Impala, Caprice, and Olsmobile Cutlass. I have $700 in the install...this includes getting the tranny (got a good deal), the rebuild kit, torque converter, TV cable, shifter plate, and all other needed parts. I went to the local parts store for the torque converter (ask for a converter for a 85 Monte Carlo).
There is a kit I bought from Rick's 1st gen to mod the shifter linkage and tranny linkage...I think it was $80. It's a nice kit and comes with instructions. Rick also sells the new lense for the gear selector for the horseshoe shifter ($15).
As another side note. Chevy High Performance is who pumped me up to do this swap. They printed all the articles to do the swap myself. From rewiring the lock up torque converter, adjusting the TV cable, to using the TH400 crossmember. This is by far one of the best resources for 1st gen Camaro technical articles!! Also excellent for GM A body vehicles too!