If you go the standard cobra oval, the below dimensions and link should help.
Tony Branda Oval 20.8 x 9.5 x 2.25
S&B Oval Air Filter Element (Tall)
https://store.cobranda.com/sbovairfielt.html
K&N
E-1963 20.8 x 9.5 x 3
E-1960 20.8 x 9.5 x 1.8 (Standard)