1971 302, points dist with drop in conversion.

I was replacing the coil just to rule it out in a performance issue, bought a new coil and asked about a new Bal resistor..the book showed a long wire type of unit, I have always had a small ceramic block style, which one is the correct one, and does it make a difference?

Its had a ceramic style for years, but will that harm anything, or is it all in the amount of resistance?

I did have a spare ceramic style I thought was right for the truck, I put it in with the new coil and it started smoking a little right away, is that just because it was new? Or because it was the wrong one? I pulled the new coil and BR right away..
Thanks!

 

Originally most of the cars I see used the special resistance wire that is installed in the harness. There are some exceptions with Ford and GM vehicles, and Chrysler seemed to use the white block most of the time.

It does not make any difference which one you use, just so long as you know what you have in the first place. Putting a white block resistor inline with the coil, and unknowingly still having the resistance wire in the harness would weaken the spark too much.

The resistance value is very small, and sometimes hard to read on a normal meter. The best way I know how to test if you already have a resistor in the harness is to hook the coil up directly, get the engine running, and then measure the voltage at the coil + terminal. If it's 12 volts or higher, you do not have the resistor. If it's something lower like 8 or 9 volts, then you do already have the resistor in the harness.

A new resistor will normally smoke a little bit. It is also a good idea to mount it on the firewall or some place where it cannot get near something that could melt. They do get hot.

Some of the later electronic ignition systems, and some of the aftermarket systems do not require a resistor. You need to read the instructions to find out.

 

I do now, and always have had a firewall mounted ceramic block style (the truck is a 56') Can I measure the resistance of this unit with a meter and replace it with the same?

 

You can. I don't know what the exact resistance should be for your application, but the schematics for a duraspark II system call for 1.05 to 1.15 ohms resistance.