Extra distributor wiring

GMC guy

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#1
Make
Pontiac
Model
Parisienne
Year
1968
Miles
70k
Engine
350
I installed a 350 engine into a 1968 pontiac from a 1983 gmc1500 truck. The engine came with a distributor with two sets of wiring, i think 7 pin module. My older 350 had the distributor with 3 wire - 4 pin module.

I tried to start the car. Checked my spark at # 1 plug. Its there but it looks pretty weak. A dim orange spark.
I was told i have to use the distributor the engine came with, as it has a brass cam gear. If i use my old distributor i would damage the engine. When i compare the two distributors they sure look alike.

So my question is, is it advisable to just switch out the gear on the distributor? I dont want to damage my engine.
 
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#2
There may be a indiscernible, but important difference in the "cut of the gear". I would consider the possibility of adding whatever is necessary to outfit the old car with the 83 truck ignition system.
I would be afraid to cause a problem when whackin the pin out and into those old parts.
 
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#3
As the dist "triggers" the coil, maybe look at the secondary for the weak spark.

BEFORE re engineering - the question now is what coil, full 12v or stepped down voltage, rotor alignment, wires and finally plugs and gap.
 

billr

wrench
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#4
" full 12v or stepped down voltage,"

Good point! A '68 would almost certainly have come with breaker-points and a ballast resistor. Such an easy fix this could be...