That dome section is pretty thick- - - -I doubt if it will cause any noticeable problems. It might allow some carbon deposits to build up, but with the fairly low compression ratio the GMC engine has, that shouldn't cause any detonation or other difficulties.
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!