2013 where to get newest info and unit?
 

Help I'm not following this. I just want to buy a ODBI unit for a 1993 chevy 454 Pace Arrow RV.

This is a MPGuino/OBDuino/Scangauge-related forum.
OBDuino and Scangauge neither does not support OBDI, only OBDII.

MPGuino supports everything as long as you can get electrical pulses from fuel injection.

There is no up-to-date sites regarding MPGuino or OBDuino. Best you can get is to read the stickies on this forum category and few posts, and the wikies:
MPGuino - EcoModder
OBDuino32K - opengauge - Homepage of the OBDuino32K Project - Open Source Fuel Efficiency Instrumentation - Google Project Hosting

Here i know atleast three MPGuino sellers, JellyBeanDriver, Meelis, and me.