Ok I unhooked the vacuum and got the engine up to 2300rpm and I was reading 38 degrees advance. Wonder what the specs are on this distributor for mechanical and vacuum advance since it's not the stock one.
That's more like it. A golf tee is a handy way to plug the hose while the advance is disconnected so there is no vacuum leak.
My edition of the DC/MP Engine book doesn't specifically include that distributor, but I think that's just a part of the poor copying and editing when the book was put together from the Direct Connection bulletins. It probably has a curve similar to the other MP vacuum advance equiped distributors of the time.
If you have a chance, measure the timing around 1000, 1600, 2000 and 2800 rpm. Then you'll have a better sense of the curve. It's a two stage curve. The second stage slows the advance - more so on engines that pick up efficiency in the higher rpm ranges.
The MP instructions from my kit (mid 80s) suggest timing of 38* between 2600 and 2800 rpm for B/RB engines.
Then the suggest adjusting the vacuum advance so at steady cruise, the timing with vacuum advance hooked up is around 56* BTDC for a B/RB.
