i have a 91 civic with a 97 itr motor. Not wanting to put up with wiring issues i kept the motor obdII but now i want to tune it. i keep reading and people keeps saying that its better if i convert back to obdI. im trying to weight out 3 options 1- to convert back to obdI n buy dizzy and harnes that goes to ecu/ecu and tune it with a base map like crome. 2- buy an s300 and a p28 ecu cause the s300 dont fit in jdm ecu. 3- just keep the p73 ecu and keep adding bolt ons. would like to get some feed back. i have i/h/e and 255 walbro pump. the car is a daily driver and it rarely sees the track. I have plans of a head built in the future. thanks

 

You don't need to buy an obd1 distributor an obd2 distributor will work with an obd1 ecu.
You can't run hondata s300 in an obd2 ecu, however you can run s300J in an obd1 JDM ecu.

Ultimately a chipped obd1 ecu and a dyno tune would be ideal.
Even better would be something like a hondata s300 & a dyno tune.