I am surprised it was even able to idle steady even when fully warmed up with that timing setting, or that it was not back firing when you hit the throttle!!
I would go for 10 degrees, and then run some 89 rated fuel and listen for part throttle ping or full throttle knock, also check the plugs after some full throttle loading and 4500 shift point for signs of detonation.
If that all goes well then hook the vacuum advance up ,check and note that it's working and note how much timing it's adding and drive the car and listen for part throttle pinging taking place.
It helps to have someone drive next to you to listen.
You probably don't want to see more then 10 degrees of vacuum advance showing up if the motor as a factory Cam, so you may need to exchange that factory one for a aftermarket adjustable one.
If all is happy on 89 octane fuel then run 91 all the time just to be on we'll safe side of things with the factory cast Pistons.
You will drop off maybe 2 hp with the extra octane but be safe and happy!
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!
1) 1940s 100% silver 4 cup tea server set.
Two dry rotted 14 x 10 Micky Thompson slicks.
1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.
Education is what your left with once you forget things!
Last edited by steve25; 10-20-2021 at 06:29 AM.
|