Here is a schema that will work. Get some 1-1/2 by one inch
4130 0.065 wall 4130 steel tubing from ACS.
It weighs about 1.2 pounds per foot but only about three feet
is needed at 3.6 pounds total. 

The drawback is it overloads the lower stock firewall hard 
point. Much better to beef up the lower fuselage to take the 
compressive loads. Three point six pounds is a LOT of carbon fiber
and much much much stronger.

Paul Lamar
 
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