Swapping the Instrument Cluster

I know this is a dead forum, but maybe someone can help me.

I'm wanting to replace my stock 115mph Instrument Cluster from my 95 Mighty Max with this 1990 MITSUBISHI ECLIPSE INSTRUMENT CLUSTER. (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7919449587&rd=1&sspagename=STRK%3AMEBI%3AIT) I know going from 115 to 140 on the speedo and having a different size diameter of gauge will completely throw my speedometer readings off, but is it possible all I would have to do is swap the ECU from an Eclipse to my Mighty Max? You think it would be a smooth transition. Anyone have some knowledge they would like to share on this idea?

Forget about swapping the ECU!!! This should be a mechanical cable operated speedo so recalibration will require some alteration of the drive gear to compensate for the different application.

an eclipse ecu swap will gain you hp and higher revs...