There is a 1/2" difference in the length of the distributor shafts between the 289-302's and the later 5.0 (aka 302) so if you want to run an HEI to eliminate extra wiring clutter and to have a simple one wire install this company does have both available:http://www.topstreetperformance.com...s/tsp-hei-distributor-sb-ford-289-n-302ci.php And http://www.topstreetperformance.com...ributor-ford-5-0l-efi-to-carb-conversions.php I posted this as an update to an earlier discussion as many of HEI's out there do not address this issue if you install the incorrect unit in the EFI 5.0 there will be almost minimal tooth contact which can cause some nasty damage,not sure what you have? Pull the distributor and put a thick coat of white grease on the gear pull it back out to see the contact pattern.A link will be posted in the FAQ Sticky
Almost all aftermarket HEI's now have steel gears,you can use a steel gear distributor on early SBF's but not the other way around, you can't use the early iron gears on roller motors.
I was going to use the steel gear off my 91 302 dist.on a Duraspark dist. The shafts are a different diameter, so I got one from Summit to fit the Duraspark. .
FWIW, if you want to use a Duraspark system in a late-model SBF roller engine...basically, all 5.0L engines used in Mustang from 1985-1995, simply go to the local parts house, and request a distributor for a 1985 Mustang GT 5sp (not the automatic GT). That particular year car, with the 5sp, had a roller cammed 5.0L, with a carb, and the Duraspark. It's what I ran in my CMC racecar for 11 years. Damn reliable stuff. And, picking up the right distributor from the parts house is even easier than swapping gears, as installing it in the exact correct location on the shaft can be a challenge.
That would have saved me a headache. That steel gear almost cost as much as a new 85 Mustang GT w/5 speed dist.
The ones I posted in the original post run $86 total for a complete distributor,the point was about getting the correct length.Many times one of the first projects with these old Fords is doing a complete re-wiring,to save having to install more wiring clutter and external control boxes these HEI's have become popular because after dropping one in all there is to hook up is one wire to a 12 volt keyed source.They use the same over the counter parts as Chevy did for a number of years,inexpensive and EZ to find at any parts house.
I have the Duraspark in mine and Jeff is right. Having only one wire and no control module would have definitely cleaned up, and simplified, my rewiring project.
I don't use the ugly Dara Spark wire harness or box. I run the Ford Dara-Spark dist with a 4 pin GM module.
I started with HEI, switched over to the duraspark also. Got one from craigs for dirt cheap, used as core for a new one. Got the 85 GT one with the right gear for the roller motor. In a couple of hours I re-curved it to suit my needs. Running it an MSD 6AL ignition box, MSD coil, and MSD wiring adapter which is a neat plug and play for MSD box to Duraspark dizzy. Very clean, cheap, and should be very reliable. Well, cheap as in I already had and was going to run MSD stuff anyway for the stroker motor. And I can run the rev limiter pills in the MSD box for those fun days . This is all ***uming the car ever meets the road again, does anyone have any spare time and motivation so email me?