Lean burn to old style ign swap?

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BigBlockMopar28

BigBlockMopar28

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Swapping an 87 lean burn 318 (carb'd) to regular old style electronic ign, already have a single pickup vac/ advance distributor, ign coil, and 4 prong ballast resistor, all I need now is the ignition module, correct? I see amazon has the genuine mopar orange box unit. Any tips or missing parts i need for this? TIA
 
I would not. I'd use the Mopar dist, all right, but use a GM HEI module instead

4pin-jpg.jpg
 
Why the gm module? Also, not sure what i'm getting myself into as far as using plugs that mine doesn't have (ex the connector for the mopar module if i was to go that route), and what sensors that the current brainbox uses that would be used/discarded. Never messed with this stuff so any basic tips and such are greatly appreciated
 
BigBlockMopar28 said:
Why the gm module? Also, not sure what i'm getting myself into as far as using plugs that mine doesn't have (ex the connector for the mopar module if i was to go that route), and what sensors that the current brainbox uses that would be used/discarded. Never messed with this stuff so any basic tips and such are greatly appreciated
Click to expand...

The GM wiring is actually simpler than the Mopar. You don't need a resistor, and you can actually use the stock Mopar coil. Just wire it up as per the diagram, pay attention to the connection polarity at the distributor. Make sure to mount the module on a flat area for heat sink, AKA a scrap piece of aluminum plate, etc. There's a plastic "tit" you'll have to break off the bottom. Only connector you'll need is to mate the the new distributor, and you could cut one off the old lean burn dist or your harness
 
The diagram Del posted above,tells you everything "you're getting yourself into". Which ain't much. LOOK at the diagram. It's all there. LOOK at the diagram. It's very simple.

As to the why. You can almost get an HEI module at WalMart. Everybody has them and they're cheap.

BigBlockMopar28 said:
Why the gm module? Also, not sure what i'm getting myself into as far as using plugs that mine doesn't have (ex the connector for the mopar module if i was to go that route), and what sensors that the current brainbox uses that would be used/discarded. Never messed with this stuff so any basic tips and such are greatly appreciated
Click to expand...
 
You will need to check your carb, to see if you have a "ported" vacuum connection, for the distributor. Most lean burn carbs did not have one. This is required for proper dist operation. You may need to get a earlier year non lean burn carb.
I do agree on the HEI system, over the chrysler.
 
Charrlie_S said:
You will need to check your carb, to see if you have a "ported" vacuum connection, for the distributor. Most lean burn carbs did not have one. This is required for proper dist operation. You may need to get a earlier year non lean burn carb.
I do agree on the HEI system, over the chrysler.
Click to expand...
Carb is a 600 holley with the vacuum port
 
BigBlockMopar28 said:
Why the gm module? Also, not sure what i'm getting myself into as far as using plugs that mine doesn't have (ex the connector for the mopar module if i was to go that route), and what sensors that the current brainbox uses that would be used/discarded. Never messed with this stuff so any basic tips and such are greatly appreciated
Click to expand...

There is only one thing the Mopar box does, and that is tell the coil to fire when the distributor says so.
(The same thing the GM module does but it's only 1.5 x 2.5" and needs about 15 feet less wiring and no ballast resistor)
 
The later 8-pin GM HEI module is better, simpler, and more robust wiring than the 4-pin. Get the parts from a 85-95 V-8 truck. Many posts. TrailBeast sells as a kit if scared of junkyards. You can connect computer spark control (Holley Commander 950, other EFI), then your lean-burn distributor is fine. Otherwise, get an earlier distributor w/ vacuum advance. I don't even know if the lean-burn distributor has mechanical advance, since might have been done inside the "spark computer" box. I think it is also a Hall-effect signal, which may not work w/ an HEI or Mopar module. Both of those are designed for a "variable reluctance" signal (mag pickup).
 
Update, did the swap, everything went suprisingly well, went with the 4 pin gm module. Didn't completely fix the issues i was having with the lb but it def helped. Thanks again!
 
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