I am in the process of re-installing my LT1 and 6-speed back into my '93 Formula. I bought the car new and after 186,000 miles, the engine had some valve closure problems. Anyway, I got to the point where I needed to replace the pilot bushing, but could not get it out. I tried two different types of pullers, but neither would move the bushing. The inside edge of the bushing would break off and the puller would slide out.
I went ahead and tapped the inside of the bushing with a 5/6-11 UNC (coarse thread) tap. It was easy to do since the bushing is bronze or similar. I used a 3" long bolt with a 5/8"-11 thread. I screwed it into the bushing until it stopped against the crank. I kept turning it with a wrench and the bolt just pushed the bushing out. Worked like a charm and was very easy.
Note:
A 5/8"-11 tap will not tap a very deep thread form, but it was enough. If you have to go larger, the next size up I had was a 3/4"-10. If you have to go to a larger size, you might have to drill out the hole.
Don't forget to blow out all the shavings after the bushing is out.
E.