[RICK LAKE]

98ACOUPE Stu, Is the motor in the car? If it's on an motor stand this make this easy to do. In the car it's a pain. You have a top loader trans, so the length of the input is no problem. The .380" trim was for GM imput shafts in FE motors with lakewood housings.
The first thing is to clock the starter and get the starter soleniod away from the block. Next is to see if the starter is flat against the bellhousing surface. This is where a little grinding may be needed to clear the starter. Once the starter sits flat on the bell housing, You have 2 choices to either remove the starter mounting plate and have it machined down the thickness of the motor block plate. Reinstall. The other way is to mark the opening where the starter goes. Remove the bellhousing and plate and cut, grind, or saw off the extra metal. DON'T do this until the bell housing has been centered to the block!!! Again you will need to recheck the starter for clearance and to see it sits flush on bellhousing surface. It takes some time, but in the long run will save you replacing the bendix of the starter. Side note and this is hard to do, you want between .035-.055" of clearance with the stater engaged into the flywheel. Its the thickness of a paperclip. Need clutch to be off flywheel for this check. Again sorry for no pictures. Rick L.