I like the spacer you are using. I used the plain old 4 hole spacers & open spacers, had better torque & crisper fuel metering w/the 4 hole ones.
One other thing I would do to your intake manifold is to grind the sharp edges on all 3 intake port runners.
I like to add aluminum weld to the base of the square flange area (carb area) because it will break through the runner when you grind big radius' in all 3 runners. (Hope that makes sense)
You wife is correct about needing to shift again, LOL, & you are not even going the speed limit @ 55 MPH, correct? THE overdrive will be a blessing.
In regards to a using inline 6 stock damper,,Maybe since your engine has a shorter stroke than a 250 does, With my 250s I could never really rev it too high because the engine would just vibrate so much over 5500 RPM & I would always have to shift it early because it would vibrate & not make anymore power.
After swapping to a standard SBC 8" 300 HP 350 damper the engine would go to 7000 RPM w/power. Big improvement!
