increase HP in a 1978 240D?
 

I have two 240 Ds, a 1980 and a 1982. I just put in a 1978 engine into my 1980 and the transplant went reasonably well as the 1978 engine is very tight and probably was rebuilt as it starts well, doesn't smoke and chain timing is to new specs and the valves were perfectly adjusted. Both are manual tranny cars. My complaint is that the 1978 motor is significantly less powerful than my 1982. I think I read the last 240D engines have 7 or 8 more hp than the early 240 engines. What can be done to grab a little more hp for my 1978 engine? The bugs are starting to build up on the rear window but my 1982 is still clean.

Have you compared timing chain stretch on both engines? Also make sure both IP's are timed out to specs. Have you done a compression check to make sure it's all still there?