I'm replacing my carb for cheap in a week or two and the person i'm buying it from says I don't need to use my advance mechanism. It's on it's way out anyway, but I thought that it was desparetly needed. and if you block off all the vacuum ports on the carb does it give any added ponies?

 

hard to say what your experience will be but my truck would not idle without it; both with the factory aisin and a weber.

 

You need to use the vacuum advance, it advances the timming at higher rpm`s , but i can tell you this, if you need to replace the vacuum advance because its bad, the only place i could find it was through the dealer and it was a two hundred dollar part. it would be cheaper to replace the whole distributor.

 

The vacuum advance helps with gas mileage and smog. The 22R uses two vacuum advance diaphrams. One (I believe the inner) is only pulled at idle, which is mainly for smog. The other one is pulled at all other throttle positions which gives you better gas mileage along with other advantages.

I bought a new one for my truck at Napa, but it was about $120. They are different for California and Federal smog and I believe they are different for certain years of 22Rs.

I remember when my distributor was not advancing correctly and my vacuum advance was blown, I went to buy a new distributor for my truck. The parts store only had one distributor that would fit all 22Rs even though the part numbers were different. Long story short, I ended up re-greasing my original distributor and buying a new vacuum advance only for California smog. If you want to go cheap, the distributor they give you in the parts store will work fine, but might not be optimal.