Got the Crane race version with locked out timing because I like the large cap and to see what it was like. No instructions came with it but can be downloaded online which showed the street/strip version has 9 timing curve choices. One is for locked out timing and there is another that might be useful for more performance oriented cars. It gives 20* advance and starts at about 1300 RPM and is fully in at about 2800 RPM so you can run a decent amount of initial.
The distributor is well built but the design is different from other FE distributors which use thrust collars which can be moved or combined with shims to determine endplay. The Crane unit uses only shims and the unit I have had only about 0.003" endplay. Also the distributor gear was way too low on the shaft. The gear is supposed to work with steel roller cams and sits on a 0.53 shaft and is held with a 3/16" roll pin. There was no way this distributor would have worked as is. I think it would be pretty difficult to locate the gear in the correct location with only that much endplay.
If you look at the photo above, there is a sensor ( the small black rectangle object near the top) that is triggered by a shutter disc that rotates with the shaft. The shims for endplay are below the shutter. I found that if you increase the endplay the shutter disc begins to flop around since it isn't attached to anything. So that's probably why there is so little endplay. There is an aluminum part which holds the rotor that is above the shutter disc that is held by a roll pin. If you look closely you can see the four screws I added from the bottom to hold the shutter to that aluminum part. I was able to get about .014 or so endplay but any more than that, the edge of the shutter would begin to scrape the metal below.
I think Ford called for about 0.022-0.032 endplay but a little less should work fine. It just makes placement of the gear a bit more difficult since you have less leeway. I didn't want to drill another 3/16" hole in the shaft so I tried to just drill another hole in the gear but that's not very easy since it has to be pretty exact. Tried an couple times and gave up. I think I will have to go ahead and drill the shaft to get it correct.
The best way I've found to double check gear placement is to seat the distributor in the engine and make sure you still have endplay when the retainer is bolted down. And check with a dial indicator that the endplay has decreased from what it was on the table which shows that the gear is contacting the thrust surface on the block. You have to ensure that it is the actual movement of the shaft itself and not the movement of the advance mechanism.
So for now I'm just running a Ford unit with the large cap adapter which works just fine. LOL
