Drill another hole in the upper arms about an inch or a little more closer to the standoffs. That will allow you to move the pivot tube up closer to the top of the engine block and minimize the top heavy condition.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!