I have a 235 with a 320 engine and constant speed
propeller and big battery in the tail. The fuel
reconfig is for CG purposes. I am in pretty good shape
but I often fly alone with 15 or so gallons. In that
config I am on the front edge of the envelope. I would
rather have a near empty header and pull from the
wings  which would put me in middle of the envelope.

Randy,

 

OK, every flight may be a test flight.  Consider that the long engine mount moved the CG forward (300 series) by 1.5 inches with no problems reported.  Although your 235 may handle differently, the 300 series certainly prefer a more forward CG than one nearing the rear of the range. 

 

Are you having problems at the round out during landing because there is not enough elevator to compensate for fwd CG (header full)?  If the plane needs more nose up pitch, consider not using full flaps (they are the biggest trim device we have) when landing.

 

If you are concerned about cruise flight trim, take her up with a digital level lined up with the longeron.  Flaps reflexed and the aircraft trimmed in cruise at 7000 to 9000 MSL, the level should be level.  One way to test this is to carry weights aloft (in the passenger seat) and move them into the passenger foot well to simulate the full header.

 

I forgot to mention that one purpose of the header was to allow the wee Lancair to fly aerobatics since the header just becomes a deep sump.  With no fuel in the wings there are no mis-distributions of fuel during exotic maneuvers..

 

The front edge of the envelope seems better than unporting the engine fuel supply at some, uh, inopportune time.