I have a 1990 motor home with a gen 1 Cummins with an Allison trans I am looking for another 25 to 30 hp the fuel screw seems to be where to get this but how far do I screw it in I don’t want to go to far please someone kelp me out

 

Install a pyrometer in the exhaust manifold. Then you can mess with the pump. The pyro will tell you how far you can go without melting it all down.