Just some notes about the bottom cover.
As near as I can tell these have been reproduced previously, probably three times not including myself or the original manufacturer, RC.
If you have bottom cover and it doesn't seem to fit well around the perimeter of the bellhousing, well - that's the way they were. My speculation is that RC re-used a bottom cover from another engine application or they ground off some sections for header clearance. The important part is that the groove for block shield matches up with the bellhousing. The steel production block shield is the one to use, but the bottom needs trimmed to fit the RC cover. If you have installed the bellhousing with the untrimmed block shield and want to use the RC cover, unfortunately you will have to remove the assembly and trim the shield. The shield is required to index the starter.
When I make the bottom covers, the foundry does not heat treat them. It's already difficult enough to get the foundry to even make the covers right in less than two months. Over time the aluminum naturally hardens.
There is a an odd center bolt hole situation on the bottom covers. When the bolt is tightened and seated, it gouges into the radius of the cover. Again, that's the way the originals were. I tried once to fly cut a cover for a good seating surface, but it just did not look correct.
