So... this is something I have thought about a bit and could be a viable option. The 4G54 and the 4G64 both share the same transmission mounting pattern. You 'could' neanderthal tech a 4G64 (which is a fuel injected engine) to run a vacuum advanced distributor and intake manifold/carb from a G63B engine. It would be better to use a Weber carb like the 38DGES instead of the kinda crap Mikuni factory carb. Bonuses - timing belts and general maintenance on the 4G64 is a cake walk. The 4G64 2.4 is a much newer engine which means easier to source parts and will be more efficient. Only other thing you will need to factor in is a matching exhaust manifold for the 2.4 and the starter motor. The 2.4 should be lighter and more throttle responsive than the 2.6. The 2.4 was used in the Mighty Max and a bunch of Mitsubishi vans so the odds of finding one is in your favour. Going carb will eliminate the headaches of electrical system mods and adding the EMS/electric fuel pump and high pressure lines etc. I think it's plausible, but if any members have added input on this idea please add your insight on it