Ream crankshaft for pilot bushing?

I'm putting a new manual transmission behind my 360. It has a crankshaft for an automatic transmission. It has a standard in it now. In order to put the pilot bushing in it I had to cut the bushing down dangerously thin on a lathe to fit it in. This time I want to ream the crankshaft to fit the proper sized bushing in. I don't want to use a drill bit as I am afraid the whole will be crooked and the vibration will tear up the transmission. How can I ream the crankshaft and keep it perfectly square? The closest thing I found was a wheel cylinder honer at the local autoparts store, but I fear the rock will wear out before I've cut the whole big enough. I've been looking at different reamers online but none will work for what I have to do.

Any suggestions?