I went the cheap route when I switched over to a glide behind my 408. The ATI plate works very nice and can serve as a mid plate if desired. I have 2 plate systems for my big block too but I switched my main powerglide over to the safety bell set-up.

1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time