many years ago I raced a A833 behind a 340 first in a Dart and then in an Anglia, not to brag but I was pretty good shifting it. Then 35 years I raced automatics. Then to regain my youth I guess I built a 340 cuda 4 speed for the street. When I built the A833 it got all new syncro's. And it just shifts hard under power, I can get all the gears, but it is just not as smooth as I remember my old dart. I wonder if it is the quality of the aftermarket syncro's? When I get a chance I am going to pull mine out and use some good used ones that I have saved. The proper way to check the brass syncro's is to hold the gear with the cone side up and lightly press down and turn it should lock on the cone with little effort, polishing the cone is necessary sometimes as it gets a residue coating from old gear lube and heat. There is also a feeler gauge measurement between the brass ring and the syncro teeth on the gear. Let us know if you fix your issue.