I was able to spend a few minutes out in the garage tonight.
I ground the bell housing out and am able to fit my direct drive starter in but not my gear reduction starter. I haven't tried cranking the engine over yet with the direct drive starter but it looks like it will be fine.
The gear reduction starter hits the flywheel before the bolt holes line up. I really wanted to use the 6.5 starter. there must be a different part number for a manual transmission 6.5 starter?