getting my truck registered in CT

how would i get my truck registered,with a diff gm, 4.3 in my mazda b-22. cause if i can't get it registered then i may have to keep the 2.2 and just do a rebuild, and keep my weber,and my catback, so how do you get a vehicle with a diff engine than what cam in it registered, are there loop holes, cause i see that quite a few people have done engine swaps on there mazdas,and other trucks.