I'm running Autolite 45s and 13BTDC with good results on high compression. My old 300 ran very well at 18BTDC. For these old engines, the best way to time them is to turn it to where it runs best, then back off till it stops pinging. An EGR might change the way you have to time it, but you can be a little more aggressive with that.
As you looking at your distributor, there is a plug for your tfi (ignition control) in that same loom/bundel there it is. Could also be wraped in tape but its there. It should be the only thing that looks like it doesnt have a place to go.
My old 94 liked 12 deg BTDC with Motorcraft copper core plugs gapped at .050. It had a good quality Taylor low resistance sprial wire set with OEM type (brass contacts) cap and rotor. Truck was a sb reg cab and weighed about 4000lb. It had 3.55 gears and 235/15/75 tires. The timing and wire change increased acceleration slightly and the truck was capable of delivering 20 mpg at 60 mph.
My 95 is an extended cab with a sb and it has 3.08 gears. I used the same formula as the 94 but i had to back off the timing to 10 BTDC. I used Autolites this time (on sale) set to the same gap. It averages about a mpg less but actually performs slightly better than the 94.
I did consider a "performance coil" but my originals always tested fine and had no trouble with the .050 gap. Some users will open the gap to .055 on the plugs but I was concerned about cold weather starts. You can adjust the timing by using a vacuum gauge and the "sixliter tune up" has been a popular mod.
For those of us that have an old Carb'd motor I've heard rumor that its best to run EFI plugs as they reach a little longer and give a better burn. I'm going to be trying this out with my engine. I know I've read about it over at Ford Six for sure.
The "Sixliter tuneup" refers to a write up done by Sixliter for the 302 but it will work for other engines as well.
It consists of low resistance ignition wires a MSD rotor, cap, coil, and Motorcraft copper plugs.
The plug gap is set to .055 instead of .044 and timing is set at 14 BTDC instead of 10 BTDC. The low resistance wires and aftermarket coil allow the larger gap to work producing a bigger spark. Most users report better performance and gas mileage
For more details doe a search on any of the Ford sites.