72 base 350 spark plug shields

[Jeff W.]

In cleaning up my heat shields it look like someone had painted them an alum. color, very poorly I might say. After taking the paint off they became a shiney metal, not quite chrome, but a chrome look. What color are they suppose to be? Also, I have seen 350's with the left front shield highly arched and all of mine are the same flat top. Can someone give me the scoop as I do not see this addressed in the TIM?
One last question, the brace for the distributor sheilding on the right hand side, should it be in the last manifold bolt or the second to last?
Thanks for the help.
Jeff

[Harmon C.]

Re: 72 base 350 spark plug shields

Jeff
I have seen the shields with a cad or galvenized finish. In the locations where their is a temperature sender the shield has a hole for the wire and is as you described.
Lyle

[Chuck S.]

Re: 72 base 350 spark plug shields

The inner heat shield is zinc. The outer radio interference suppression cover is flash chrome which is not real high quality and not buffed.

On a 72, you should have the heat shields over all plug wires in pairs (AIM UPC 6, page B6), but the radio noise suppression covers are only on the rear pairs of plug wires (AIM UPC U69, page A5). You shouldn't have any front suppression covers, and the right rear should have a rounded extension on the top with an opening for the TCS temperature sensor wire. You shoule have vertical channels covering the wires coming down from the distributor shield, and "Vee" shaped channels on each side that cover the plug wires from the rear of the engine to the motor mount.

The distributor shield support on the right side is more rearward than the left, and as best I can tell, the bolt is the last bolt on the right side. It should be obvious if you hold the distributor support in position with the left support installed. If you look at the distributor shield, you will see that it's made to have the LH support forward, and the RH support rearward.

[Jeff W.]

Re: 72 base 350 spark plug shields

Thank you both. As always I can count on this board for help. Would it be smarter to buy new heat shields from Doc or find someone to zinc plate my originals?

[Chuck S.]

Re: 72 base 350 spark plug shields

In general, it is always better to refinish original parts, than buy new replacements.

In this case, however, there is no guarantee that the parts you now have are original to the car...if you have radio suppression covers on the two front pair of plug wires, someone obviously put together some parts to replace the ignition shielding. Typically, the ignition shielding would be discarded at the first spark plug change because it's a PITA to put back. I wouldn't expect the heat shields to have been removed.

It is not always easy to find a zinc plater; particularly for only a few parts. If you can have someone knowledgeable confirm that the heat shields are correct for your car, then doing a little calling might turn up a good plating deal locally. That would be preferable to replacing the shields.

Otherwise, the Doc still has a few NOS parts available; if he has the NOS parts for your car, then that would be the best course if you're not sure the existing shields are correct, or if the shields can't be replated for a reasonable price compared to NOS.

[Jeff W.]

Re: 72 base 350 spark plug shields

Thanks Chuck