I used a similar spacer plate a friend machined, that also meant I did not have to lengthen the splines or shorten the input shaft. Also found an Astro van clutch disc. Love the T-5 in my 46 pickup.

It's easier to get forgiveness than permission!
1946 1/2-Ton Chevy
1953 Chevy 3/4-ton Factory Stakebed