I had a 91 Caprice (Land Yaht) it had a 305 Tuned port injection. It was a really good running 305. Low end torque was good and seemed to have pretty good power range. I then got a 93 Chevy Silverado with a 305, I didn't get the same level of performance from it, it is a dog. However, it has been going ever since I got it with 15 miles on the odometer and I have over 178000 or so miles and I have had zero problems with the engine.
So I have mixed emotions about the 305. Performance wise I would guess that you could get one that really rocks or you could get one like the one on my pick up. I have been through 2 700R4s (Well 4L60E actually) in that pickup. I am not truely impressed with that transmission, but it is better than having a 350 turbo. I only haul a Bass Boat and it is a small 16' job. So I shouldn't have had that kind of issues with that transmission.
when you rebuild a motor you replace any parts that are bad on your motor at the time or that need replacing. i think you covered it all though. did you install all of the parts yourself? how much did it cost for all of the parts, b/c i was thinking about doing it to my 305ci.