While I was able to find some information on a single vs dual vac distributor, I do need some help with my specifics.

I believe I have a single vac distributor:

http://i187.photobucket.com/albums/x...xum96/dist.jpg

This is just a photo I found off another site, but my distributor is almost the exact same - 2 hoses attached.

I read there are some benefits to having a single vac distributor, if I have a dual vac can I switch to a single pretty easily? Or do I already have a single vac?

There is also an option of "w/o vac distributor":

http://www.rockauto.com/getimage/get...de_1818394.jpg

1970 Ford F100 302 5.0L v8

 

Hey there. Your pics were blocked from me here at work. Never bothered to buy one of my own since I have low patience level with computors. Anyways, so I couldn't see your pics. A Dual vacuum advance has two hoses. One up front like normal on the advancing side of it's diaghragm. And the second nipple sticking out the top on the retarding side of the diaphragm. This was to help Ford keep up with the emissions standards the Feds were pounding the Big Three with back in the day. We don't have to worry about that and would like more horsepower than was produced then. The Single vac advance is what you want and need. The No Vac advance is for race cars. Requires you to fiddle with the centrifical advance springs and total Timing Advance . Meant for full throttle. Two notes here. 1st being the vacuum advance and the points breaker plate usually wore out pretty much the same time. If you replace the vac advance and the breaker plate is wore out, as the vac advance pulls on the breaker plate it will tip instead of pivot. Messing up the point gap. Solution: Buy a Rich Porter brand NEW distributor. New Billet aluminum housing and so complete they even come with a new cap and rotor. 2ND. If you still only need the vac advance and Bill comes up with a part number and dealer that has a Genuine Ford, Ford's vac advances usually had an adjustment screw on the rubber diaphragm inside. Stick a 1/8" (as I recall) allen wrench in the front vacuum nipple. Once in the screw, Carefully spinning the allen wrench clockwise or c/clockwise you can +/- 2 degrees of DISTRIBUTOR advance on the timing to kinda tailor your distributor curve. I do not remember which direction adds or subtracts timing curve though.