Need to loose about 15 Hp

If you got the #35 venturi, then go back to a 27 or a 29.

Kinda the same thing as the restrictor plate idea.

Your restricting the amount of air that enters the engine, which will cut your high rpm power range, but you might pick up lugging power with the smaller carb setup.

Air filter placement [distance] from carb is worth around 5hp.

The rpm that you run the motor at. On a "M" anything over 1900 and you run out of cam lobe .

Timing is worth 5 to 8 hp .

This is a tuff one because anything you do will effect the big picture.

When they go to put you on the dyno why don"t you pull the choke on half way or more . I"m thinking that should faten the motor up enough to take some "HP" away.

You could also put a electral switch in that full fields the alt ,at all rpm causing a nice load on the motor.

This is the first time i have read some one wanting to loose hp.

Maybe you should have asked how to hide HP , there is plenty of people on hear that cheat like crazy for that $10.00 trophy.

Intresting question , nice for a change.

Hope some of my thought help out.