interesting idea, made with an impressive team. But it didn't take off. Probably too many crop sprayers operating dirt cheap with old planes to warrant anyone investing in an expensive upgrade

A development of the 1950s-era, purpose-built Grumman Super Ag Cat biplane, it replaced the Ag Cat’s single 600 hp Pratt & Whitney R-1340 radial engine with two 310 hp Lycoming TIO-540 flat-6 engines.

Rather than being offered as a complete, factory-built aircraft, the Twin Cat was a modification offered in the form of a supplemental type certificate (STC). The Twin Cat Corporation targeted Ag Cat operators wishing for more easily serviceable engines with increased overhaul intervals and multiengine redundancy, and the company offered to travel to the customer for on-site modification of their Ag Cats.

The Twin Cat’s total fuel consumption was the same as that of the single-engine radial Ag Cat. They also claimed the new layout improved forward visibility, prop clearance, and spray dispersion.

The company had some impressive experience at the helm. The president had overseen the development of a turboprop conversion of the Grumman Albatross and was assisted by the former chief test pilot at the general aviation division of Rockwell International. Most of the test flights were flown by Herman “Fish” Salmon, retired chief engineering test pilot of Lockheed.

https://www.flyingmag.com/the-one-brief-life-of-the-twin-cat/