72 heat shielding

[Dave Mak #30045]

[Joe L.]

Re: 72 heat shielding

Dave-----

First off, do you have the correct shields? The shields used for the front left side and the rear right side are the same and are GM #3917664. The shields used for the front right side and the rear left side are also the same and are GM #3817657. There is another shield, GM #3919807, which is supposed to fit on the front left side of 68-75 Corvettes. This is the shield with a round hole in it, presumably for the temp sender, directly above the mounting bracket. My original owner 69 DID NOT USE this shield and I've never been able to properly fit one of these to a Corvette, especially one that was equipped with front radio interference shields (your 72 doesn't use these, though).

Each of these shields attaches to the block with a single, 1/4" screw. It is generally quite simple to install them, although a bit of gentle twisting and flexing may be necessary.

[Dave Mak #30045]

Re: 72 heat shielding

Joe, It sounds like your post is referring to the smaller of the heat shields. The "J" shaped ones (four total for the car) as I put it. Those I had no problem with them. The ones I'm having trouble with are the larger "L" shaped ones(two total for the car). I believe they protect the front two wires on each side as they snake behind the center of the manifold were the tail pipe conects.

Thank you for yours help.

Dave Mak

[Joe L.]

Re: 72 heat shielding

Dave-----

The shields that you are referring to are not really heat shields; they are part of the radio interference wiring shield system. The only heat shields are the ones that I previously described. In any event, it's a very common misconception and misnomer, but, at least I understand what you're talking about now.

These shields attach to the block with two brackets which are retained by the two 1/4" hex head screws on each side of the block which also retain the heat shields that I described earlier. It can be a little tricky installing these in the car, but I've never had any real trouble doing it. One thing that MAY be tripping you up is this, though: these shields for pre-1970 Corvettes are different from those used on 70-up Corvettes. That's because in 1970 the motor mounts changed from the conventional style to the locking style. The locking style mount is much larger than the conventional style and the pre-70 shields require modification if they are to work with locking style mount. In fact, GM motor mounts of the locking style (the only style available in SERVICE for all 63+ Corvettes since 1970), actually have an instruction sheet in the box for modifying the shields. However, if you have obtained a pair of the pre-70 style shields, I suggest that you exchange them for the 70+ style.

[Robert C.]

Re: 72 heat shielding

Dave, the lower "V' shields attach to the block as Joe stated. Maybe the problem is with your plug wires routing through the end of the shield. The front two plug wires should route through the motor mount and then go directly into the front end of the shield etc. Otherwise if the spark wires aren't routed through the motor mount first, they won't fit into the shield end correctly.( you have to remove the plug end boot and lube the end before they can go through the mount hole. Hope this makes some sense! Bob


Texas Chapter NCRS

[Dave Mak #30045]

Re: 72 heat shielding

Bob, That helps allot. I assumed the when above the motor mount and therefore the shield was mounted such that it had an opening above the motor mount. I'll give it a try tonight.

Thank You

Dave Mak