I picked up a Mallory YL with a working Unilite for about $20 bucks. Does anyone know what that distributors springs equate to the more modern (YH I think...) grey/grey. I plotted 16 degrees at green/pink. Not 100% positive though... I do have the key and spring kit.

Anyone using one of these?

-Aaron

If you look at the Summit racing site they have the documentation online for those spring kits. The newer spring kit has a graph of spring rates, I'd bet the old one does too. Compare rates of advance, not total advance.

I just bought a Mallory 4554101 from a member here (new & setup by Jake) who sold it because he sold his car.

It looks like it is a YH advance assembly and it looks like I have the Orange & Gray springs installed. It also looks like the Orange spring perch (tough to tell) is slightly bent (which Mallory recommends if you want to change the RPM at which the advance starts (per the Mallory instruction sheet P/N29014).

Looking at the single stage paired springs advance curve...I would have 0 degrees advance at 800 RPM (maybe slightly higher it the spring perch is slightly bent) and approximately and 24 degrees advance at 2500 RPM.

Just trying to understand all of this. Does this sound right? Don't want to give away Jake's ancient Chinese secrets.

I've read that some folks use the gray & gray?? Is that with the YL advance assembly and not the YH??

My understanding is that the modern advance (YH) is best with grey/grey with 16 total degrees of advance (12 idle - 28 3K RPM).