DUI (Davis Ignition Sysem) Distributor Install step-by-step

[seattlescout]

I ordered a dui though IHPartsAmerica.com a few weeks ago. The box came with a custom configured dui specific to my 79 Scout, new wires, thermostat housing, and billet wire separators.

I have pulled the oem thermostat housing off and am getting ready to install the "modified" thermostat housing that came with the dui.

Note the differences in the pictures.

1. Looks like the primary difference is simply that one of cast bolt fasteners has been removed.

2. Note that the modified version as a smaller intake circumference ( the hole in the middle), looks like at half the size of my original thermostat housing. I am concerned that this May pose a restriction in coolant flow resulting in a hotter running engine. can the "experts" comment on this please?

I will post updates as the install progressed. In am in the process of installing the modified thermostat housing first and will be installing the dui/wires and new plugs in a few days. I have reviewed michael mayben's sticky's in installing dizzy's and will report back.

Also note, that if you send the original thermostat housing back to performance distributors - high performance and racing ignition systems They will extend the warranty by another year.

 

[Michael Mayben]

The diameter of the bypass hole in the thermostat housing is really of no concern. I've mixed these items around on engines for years with no reports at all of overheating or inadequate cooling system performance.

If you still have concern regarding the hole diameter, simple enlarge the opening.

Yes, davis simply removes the ear on the flange, that part is used when that thermostat housing is installed on the I-4 engine. However, this must be done very carefully or a void will form in the wall of the casting. Those are somewhat thin in cross-section and the molding process meant that no two of 'em were ever cast exactly the same, some are thinner than others.