1405 is a "universal fit" 600 cfm unit. It is a manual choke and jetted richer than the 1406. It will run fine on your 460, but will certainly be a noticeable difference from your stock as it is smaller.

As to th automatic transmission - depends on the linkage - but should be fairly straight forward to hook up.

They're $250 new, so $200 used is a bit much IMHO.

Regards,
Glenn