There are two different styles for the inline six. One has a conventional-looking cap with a center wire, and a remote coil. The other one looks like a V-8 HEI with the coil in the cap, but only 6 wires instead of 8. If you've got 3 wires in the plug coming out of the distributor, you've probably got the remote coil model. Find a Mid-70's wiring diagram for a 250 6-cylinder, and wire it accordingly. I might have a diagram I can copy and attach to an email, but it will be a week before I'm back at my school shop where the old service manuals are stored.
Jerry
PS: Even the integral-coil models have a pigtail from the distributor housing to the inner cap terminals, and there are 3 wires on that one. You might have an integral coil model already.
Jerry
