Distributor Indexing

Would a incorrect indexed distributor cause my problem of a small misfire at idle and running rich. I have a Crane Cam its not stock.
Should I trust the timing marks or use the screwdriver trick to find TDC. Should the rotor be .020 before #1 or .020 after #1. I have heard both which is correct. Does anybody have the link to the TSB for this issue.

You already got my PMs but you could also try this:

http://www.angelfire.com/my/fan/dist_index.html

kemarsh said:

Would a incorrect indexed distributor cause my problem of a small misfire at idle and running rich. I have a Crane Cam its not stock.
Should I trust the timing marks or use the screwdriver trick to find TDC. Should the rotor be .020 before #1 or .020 after #1. I have heard both which is correct. Does anybody have the link to the TSB for this issue.

Click to expand...

The real timing is done by the CPS and the ECU not the distributer.

I don't know whether all 4.0's are the same in this regard, but when I was playing around with my 87's distributor, I found that there really was only one tooth position at which it ran correctly. One tooth advanced caused it to start hard and occasionally kick back as if hydrolocked, but it ran well once going. One tooth retarded caused it to start very easily but it would not run above idle. If you think it's indexed wrong, I'd just pull it out and try it one tooth in either direction, and you should have your answer soon enough.

No doubt a full tooth off will really mess things up.
But if you need to tweak the timing a few degrees or change the curve you need to re-program the ECU chip or get an adjustable CPS.