s13 Automatic trans

[dirtracer21x]

Hi Everyone I've got a 1990 s13 with a ka24e that I race on a oval dirt track up until recently I was running a 4.63 differential gear. I've had to change back to a stock 4.08 gear and I'm not happy with the performance of the car now

I've been doing some research and I think if I swap to an automatic and run second gear ( I run 3rd on the current 5 speed) ill have close to the same final drive as I did with the 4.63 gears

so my question is

what parts other then the trans will I have to change driveshaft? trans mount? starter?

are the automatics electronically controlled or fully mechanical?

and are all all automatics ka24e and ka24de the same?

Thanks in advance