Never seen, never used & inclined to say no such thing exists.
First question - which model of Samurai is that for - many of the US models had an electronic feedback carb and cannot be chipped, there were some later EFI models, but if you think you can wring 50% more power AND better fuel economy out of any internal combustion engine by changing a chip - ummm - I've got a bridge I'd like to sell you.
I'm not saying you can't get more power out of those engines, but 50% more power - you're talking about high compression pistons, head work, camshaft, headers, intake & exhaust, and when you're done, it's going to a high rpm screamer - unsuited for most off road usage.
I think you'll find a 1.6 swap (from a Tracker or Sidekick) to be a lot more practical path to power.
