440 Engine tuning suggestions
My 440's love NGK plugs. Initial timing is found at idle with the minimum timing to obtain max vacuum. Then you MUST limit the added mechanical vacuum to not exceed 34 to 36 total. Vacuum advance needs to be reduced in most cases and run to manifold vacuum, so it falls away when the throttle is opened. to reduce tendency to detonate at higher open throttle settings where manifold vacuum approaches 0.
It's a balancing act, especially cruising on the freeway at high manifold vacuum with high gears and/or overdrive. I found that out the hard way, and never heard detonation.
My 440's love NGK plugs. Initial timing is found at idle with the minimum timing to obtain max vacuum. Then you MUST limit the added mechanical vacuum to not exceed 34 to 36 total. Vacuum advance needs to be reduced in most cases and run to manifold vacuum, so it falls away when the throttle is opened. to reduce tendency to detonate at higher open throttle settings where manifold vacuum approaches 0.
It's a balancing act, especially cruising on the freeway at high manifold vacuum with high gears and/or overdrive. I found that out the hard way, and never heard detonation.