It's great to find knowledgeable people who are willing to help. Thanks again.
-john

 

happy to hear that you got your problem fixed.

This is gonna sound dumb however what do you mean be a flutter or Grunt as the RPM's fall?

 

Rev the engine to say 1500-2000 RPM then let off the throttle completely (truck is not in gear), as the RPM fall past 1000 the engine very briefly revs by itself - sounds like it would if you bumped the trottle - and then it settles into idle.
-john

 

My truck does it around 1200 rpm as the engine drops, but only if I hold a little go pedal so it doesn't drop below 1,000 rpm. If I rev it up and let go completely it does not surge or flutter.

The next chore is working the governor lever to optimize your plate.

-John

 

My #10 plate is in stock position. I haven't checked the lever yet but I doubt it's going under the plate. Is that what you mean my 'optimize' or do you know some other tricks?
-john

 

--> Yep <--

 

Oh, come on now, that ain't fair. Spill your guts and share the wealth!
-john

 

You need to understand the governor action and movement of the lever. Idle is where the lever starts when you check with the AFC removed. Full speed is less than 1/2" up the plate.
With stock springs this is roughly 800 to 2400 rpm. GSK is same 800 but now maxes around 3200 rpm. Idea is to keep your max hp curve under 2,400 rpm where the engine breathes well and easier to control EGTs.

The fianl check requires a dyno run to map the engine curve and adjust the governor lever up as required to dial in the curve.