motor trans swap

[poco64]

Im beginning to look for a modern replacement motor- transmission to put in my 66 3/4 ton 2 wheel drive. I would like a smooth running modern replacement for my daily driver that gets fair mileage, and runs smooth. I dont need anything more than average performance. I guess I was wondering if there was one particular motor trans that I should watch for. I would like to find a salvage yard vehicle so I could get the steering column, seats computer etc. from it. thanks everyone.