I was hoping sleepy or someone i've talked to in the past few weeks about timing could help me on this. I bought an adjustable vacuum advance for my duraspark distributor and installed it today. My question is how do you set it and what are you doing when you turn it with the allen wrench, because when I turned it nothing moved unless nothing is supposed to move that you can see?

I was not gonna be able to run 16 initial with the stock vacuum advance, so I was told to get this so I could and back off the vacuum.

I'd like some responses asap because i'm goin back over to work on the truck again and get everything set right.

 

Here's everything you need to know... FORDMUSCLE webmagazine: Timing is Everything - Distributor Curving for Maximum Power

 

BLAM! There ya go. Montana has you covered! As that says, you're adjusting the tension on the diaphram spring when you turn the adj. screw.

 

That's a really informative tech article, i figured it would be better than trying to explain it.

 

thanks you guys, yea i didn't know if the arm coming out of the canister was supposed to move in or out or whatever when you turn the screw. Well i'll set the initial tomorrow at 16 and drive it and see how much vacuum it can take till it pings.

 

Yeah, I've got the same tech article bookmarked. lol I'd rep ya but it won't let me

 

Also it came with two sets of springs where if matched in certain ways you can get 3800, 3600 and 2500rpm i believe it was. which one would be better for a truck used for around town cruising and mudding?

 

Every application is unique e.g. tow rig, hi-po street truck, etc. but you can experiment with different spring rates to find your sweet spot, these are big heavy trucks, so generally speaking, full advance before 2,500 rpm is a bit too soon, i'd recommend having your advance "all in" somewhere around 3,000-3,500 rpm, it takes a little trial and error to dial it in correctly.