This is a 616 four cylinder. Make sure the fuel supply pressure is at 19 pounds in the injection pump base. Many are far below that.

Since unlike the 617s us 240d d owners spend so much time with the pedal on the floor. Do you really want a cloud of black smoke? Or if you manage it the enforcement guys might stop you.

Do a thorough check and tune up as well. These engines need to give everything they can produce. Valve clearances, timing chain stretch and general timing, free flowing fuel suppy etc. I assume from the numbers posted yours is an automatic?

The cheapest way to get a real power boost is possibly installing the turbo five cylinder and it's transmission. Other than that gains will be limited.