Which Distributor to use in 345??

[tnhotrod]

I have a distributor out of a 304 and the distributor that came out of the 345 that I have been rebuilding. I have pics of both distributors. Which distributor should I use? It will be used in a 345 Scout II 4x4

 

[Michael Mayben]

Your first pic is a prestolite electronic trigger.

The other pic is a Holley electronic trigger, aka "gold box".

Post the part numbers for each so that the version of the original advance curve May be compared.

Have you thoroughly read through these two threads in order to educate yourself?:

http://www.forums.IHPartsAmerica.com/ignition-tech/642-ihc-vehicle-distributor-identification.html

And this one:

http://www.forums.IHPartsAmerica.com/ignition-tech/644-ignition-system-performance-upgrades.html

If I had each of those distributors here and were gonna do the same as you right now, I would:

1) sterilize and rebuild the Holley unit, and set it up with a pertronix conversion (for a gold box distributor that is p/n ho-181).

2) trigger a msd/crane/mallory "6 series" cd box.

3) use a low primary resistance ignition coil (preferably an "e" core coil) triggered from the "6 series" box to take full advantage of the overall system, and fire a plug gap of no more than 0.045". "low resistance" primary numbers in the suitable coil would be something between .04 ohms and .08 ohms.

4) your choice of helical-wound secondary cabling, 7mm, 8mm, makes no difference, the stuff is all the same in actuality no matter what the marketing smokeblow sez.

This system is powered directly by the battery/ignition switch and involves no "resistance" in the primary feed circuit, no resistor wire, no ballast resistor.

That would be considered a "state-of-the-art" ignition system today incorporating components ya already have.

The prestolite distributor is an excellent product, but if it's currently functional, I would not want to use it a basis for a performance ignition system, it's best kept in oem condition and used onna dd application or by someone doing a resto.

 

[tnhotrod]

So if the main purpose was use it in the trails , mud and a lot oof water which one would you use? Both are complete and seem to check out as far endplay and wear. I am going to tear both of them down tonight and then bench test them.

 

[Michael Mayben]

For best timing stability, no IH-version distributor should have more than 0.015" of end play, measured between the gear thrust surface and the snout of the lower housing. That is way less than the "spec" called out in any service reference.

Between the two units if you are not going to build a performance ignition system, then it's a toss-up. Without any part numbers, there is no way to compare advance curve data in order to see if one might be more suitable than the other.

 

[tnhotrod]

The 2 distributor numbers are prestolite 496004c91 idn 4002r448

the other is 461270c91

thanks for your help ..

Which one now?

 

[Michael Mayben]

Go with the prestolite if the module and trigger are operational.