This motor ran fine in the bread truck but it was a allision auto, now its a nv 5 speed and it feels some kinda strong. But when i push it to the upper rpm range I get a hint of poping and white smoke. I do notice its not as bad when it has sat all night, And I do see what looks like air in the line up by the engine where I have a clear glass filter. I used a existing line as a return line on the scrambler. My theroy is the line must end just as it goes through the tank and I must be stiriing up alot of air. I can also feel the pulse of the return line back at the tank. Should i Be thinking about running a bigger line? This line i used had an id smaller than the rubber line that comes off the injection pump.