Aussi-66

I have a friend that has just purchased a 65 big block coupe. We are going to give it a service and a tune up over the weekend. I am very familiar with the data for the small block but not the big block. What is the initial advance for a BB, when should all the mechanical advance be in and what is the total advance including vacuum advance? The other dumb question I have is what should the idle vacuum be? Thanks for your advice and help.

Ironcross

spark plugs and gap....R45XLS with .035
spark lead 10 with a range 8-14 degrees
valve lash intake..... .020
valve lash exhaust......024
curb idle.....750-850
dwell 31-34

JohnZ

I don't have the original factory specs, but they run best with 24*-26* of centrifugal advance, all-in by 2800-3000 rpm (which provides 34*-36* total advance, which is measured with the vacuum advance disconnected and plugged). The vacuum advance should start pulling at 5"-6" Hg., and should be fully-deployed at 12" Hg., providing 14*-15* of advance. There's no such thing as measuring vacuum advance above idle - it drops out instantly when you put your foot in it. Idle vacuum is whatever you get, but should be around 12"-14" Hg. at 800-900 rpm.

Larry N. Johnson

425 HP at 6450 rpm on 103 octane petrol w stock 11:1 compression.

Aussi-66

Thanks guys the car is running great.