The 69 is a bigger car. If the car in question is not a factory resto then of course you can just recess that area. I have seen an F body w/a shaved firewall and they used a trimmed down torque converter inspection cover and recessed it into the firewall. It looked good. If you are desperate for another inch or so (on the car) then I have also seen guys shim the tranny up on the cross member and it will tilt the engine forward a little bit.