One of my mates in Brisbane is 6'8", 240's were about the only cheap old proper-car he used to fit into(*), for the reason that the seats (and we were talking about older ones) went so far back that even he could just about straighten his leg with foot flat on the firewall (and plus the seats have the up/down adjustment to give enough headroom).
You'd probably have looked into any seat-base differences ages ago by now, I only raise this 'cos if a 6'8" person can fit comfortably into Car A and a 6'5" person is tight in Car B, and the two cars are very very similar (without knowing exactly what year or trim-level Car A is/was unfortunately), there might be some sort of arcane/obscure seat-base or mounting or rails/runners difference.
PS. I don't think the Recaros would necessarily help, I'm using Toyota Smurf Recaros with oddly-affordable-at-the-time new Recaro rails/mounts and I don't think there's any more room than stock - you'd have to fiddle with them too methinks.
(*) Oddly/aside - he was also comfy in the first generation of Renault Clio 2dr they sold in Oz - you could adjust the front seat to touch the back seat, and the front-seat was almost on the floor when you did that. 🙂
