Stock distributor that is likely why your engine is not up to par. A stock RV distributor would be way slow to let timing advance!! You have a deeply geared and light by comparison truck. I think your timing should be all in by 2600 to 3200 RPM maybe earlier. I am betting its not all in until 4000 RPM with those stock RV springs in your distributor.
Any time a performance cam is added to an engine, the ignition system MUST be recalibrated to match the cam. The distributor you have now could most likely be modified to work with the cam. (Assuming it doesn't have excesssive wear or damage) The other option is to purchase a high performance distributor, but as you noted, these aren't cheap.
Motorhome 440's were noted for having VERY LOW compression from the factory. A larger performance cam with low compression will require a LOT of ignition timing to run even half way decent.
The fuel system will most likely require some recalibrating, modifing and adjusting after a cam swap. Carbs have to be tuned to the engine in order to achieve maximum performance. That 600 cfm Carb is almost certainly to small for a 440 with a performance cam. The cam will determine what size carb you need.
What are the specifications on the cam? What is the compression ratio?
Last edited by QuickDodge; 04/28/14 12:43 PM.
