So I unearthed my ECU today to find a Kakimoto sticker on it. It's a 91 n/a. Is it likely to do much for an n/a? The guy i bought it off did say the fuel economy was surprisingly good on long runs and i was pleasantly surprised at how little petrol i had to put in it to get it home.. Not really driven it much since as I've been restoring it, but getting it on the road soon. Is it a proper remap or just a standard plug in job?

Properly tuned na will give better throttle response and feel torquier, but if it was tuned in japan (kakimoto is a japanese tuner) they could be tuned on high octane race fuel which isn't the right tune for UK fuels.