While I had purchased an auto bell housing with an eye towards installing a Ford type 9 or rocket box but I've since started down the path of installing a 63 series 5 speed.

There is an alternate second gear for the 63 series that was installed in the Z20 powered cars. It's 1.922 which would make the ratios similar to the mid-close ratio 56 series 4 speed. I believe I actually found a dealer with the parts.

Everything else on the car is overbuilt, H190 rear end, ZX brakes, rally spec cage and so the oversize box seems appropriate.

Now if it were in a Spridget because I'm an idiot and suffer from Chapmen disease I'd want an A12 coupled to the 56 series box. Saving 28 pounds is worth listening to the motor turning 5000 rpm on the freeway.