Ignition upgrade => replace dizzy too?

[Matthew W. Woodruff]

All other things being equal, I would probably go for the TFI upgrade with the MSD 6A module.

But, the existing distributor already has 168K miles on it and will certainly crap out one day (like a rainy day with wife, kids and dog in the car).

Thus, replacing the dizzy when I do the ignition upgrade might be the cheapest way to go in the long run. That means going the HEI route instead of TFI, though.

I am leaning to the Davis DUI product for the sole reason that they say that it has been tuned to the AMC 360 specs (vac/rpm vs. advance). Not sure if the GM retrofit that is otherwise available does this (or even if it matters).

So, if I put in either the DUI or the GM HEI dizzy, am I going to have problems when I spend even more money to add a TBI fuel injection system in the future?

And, is there any real difference between the Davis and GM product when it comes to the timing/advance curve?

Thanks.

[4DWUDS]

The only problem I see is you putting your Dog out in the rain while the wife and kids push. LOL :D Not noing to much about the Davis unit but there are other members who wouldnt run anything else, and I think they are cheaper. GM HEI units burn out there little module if not properly installed but GM parts can be found at a 7-11. carry a spare. IMHO I would go with the Davis.

[Desert Beast]

what about the MSD dizzy (pro billet). i have gone that route and couldnt be happier. w/ the 6a box its a simple hookup.
just a thought

[Jeepadilly]

I also have installed a pro-billet MSD dizzy and now my Bear does more that s--t in the woods!!!!

[rustywag]

All the distributor has to do is go around. As long as the bearings are good all a billet aluminum one will do is enrich the guy who sells it to you. There is positively no way possible that a high dollar distributor can improve your engine performance over a properly tuned stock one!!! Really, NO WAY!! All it does is spin around in a circle, that's it, it just rotates. I feel so bad for all the people in the world who waste a couple a hundred bucks on a pointless high dollar distributor. Yes your stock one may need to be re-curved or have the vac advance adjusted. Both of these thing are easy and cheap. Please spend the money on a TFI cap swap an MSD controller.

[turtlejoe]

If you really need to go with a new dizzy, keep in mind that you can get a brand new, made for AMC V-8 unit from several locations for under $110. I've seen it in the PAW catalogue as well as a couple of the Jeep specialty catalogues. Even the dealers can get them, although I'm sure it will run "a bit" more.

Just a thought.

[tuckers89GW]

or you can buy a rebuilt stock one for $50 from NAPA. then add the TFI cap if you upgrade the ignition.

[ March 11, 2003, 09:33 AM: Message edited by: tuckers89GW ]

[Matthew W. Woodruff]

The way I figure it is:

TFI parts (new from Summit) = $235
[MSD 6A box, TFI coil, cap, rotor, adaptor, harness]

Davis DUI distributor = $360

spark plugs and wires = same for TFI or HEI

So, unless a new stock AMC distibutor costs more than $125, it makes sense dollarwise to go the TFI route.

Thanks.