Is it a 4500 carb?Some guys consider the 4 hole spacer a safety device to keep the internal linkage from being able to fall into the engine.That's why I got one.Probably never happen,but one nut thru the intake could be very expensive.BTW,6.00 is not SLOW!That's cruising in my book!Funny thing you're running 6 flat at 112 mph.I'm turning 105 mph,so why am I only running 6.90??That sux!!