Cut the firewall for 2 bolt Master Cylinder!

CudaChris67 said
Hours of FABO research yielded that in the event of using the adapter, a longer (adjustable mancini/MP) pushrod is needed ($75) in addition to the $40 adapter.

I'll pocket the 100 bucks and get some weld time in!

Not true.
Installed the alum m/c on my 65 and used the stock push rod.
Works fine.