1971-1972 Side Grille Differences

[Jeremy D.]

Do all the side-gill grilles for '71-'2 with both horizontal and vertical plated edges have a little ridge on the bottom surface of each "square" in the grille? If I put my finger on the bottom of each section or "square" of my '71 side grilles, there's a molded ridge on the bottom surface that my '70 grilles do not have. My '70 has smooth bottom surfaces in the grilles, but it has also has replacement side grilles with '71-'2 style vertical/horizontal plated edges (or correct '71 grilles...?). You can't see the ridge unless you're looking from the back of the grilles inside...I thought early '71's had smooth bottoms (like on my '70) even though the outside edges were chromed/plated/whatever both vertically & horizontally. My early '71 has those ridges. I'm getting the hint that the grilles on my '71 were replaced at one time or another.....correct assumption?

[Terry M.]

Re: 1971-1972 Side Grille Differences

Jeremy, are you saying there are three styles of side grilles?

[Jeremy D.]

Re: 1971-1972 Side Grille Differences

I'm trying to make darn sure there AREN'T 3 types of grilles. In the TIMJ, Pg. 42, it shows in fig. E12.1 what the '70 and '71 up to #1450 grilles look like. Then, in fig. E12.2, it shows what the '71 S/N 3600 and up grilles look like. So what are the grilles for those of us who own '71's built between #1450 and #3600 supposed to be? Pg. 41 says that the '70's and '71's up to #3600 had '70 style grilles. That includes my car ('71 #24**). Then, it says that between '71 #1447 and #1600, they changed over to the chrome vert/horizontal edged grilles. Now I'm assuming that either the #1600 or the #3600 is a typo, but I would like to know which number is the typo, as it accounts for 2000 cars, one of which is mine. I know the later cars have the grilles like I have, and the '70's are different as well. But I have in my notes from the '70-'72 LT-1 Goldschool class that the ridge on the bottom surface wasn't around until mid-'71-'72's. I just want to know what the parameters are, if my deafness led me to write down the wrong notes, and if I do or do not have the right grilles on my early '71.1971 LT-1 001.jpg

[Terry M.]

Re: 1971-1972 Side Grille Differences

The numbers in the manual represent cars we have seen that have what we believe are their original components -- typographical errors aside. If you think the parts on your car are not those originally installed, then you have to decide where your car fits in the continuum of parts supplied to St. Louis.

Consider that sometimes new parts were installed after a certain serial number, or certain date -- other times new and old parts were intermingled over a long period of time. Do we know which parts fit which situation -- NO. There is a third situation in which a number of test parts were installed some time before a change made. Our parts observations could fit any of those three situations. YOU have to decide.

As a last note -- The judging manual is not designed as a formula to produce a Corvette. Using it for that purpose -- and I am not suggesting you are -- is an exercise in futility.

[Paul O.]

Re: 1971-1972 Side Grille Differences

Jeremy I can tell you that my 71 s/n 1914 had 2nd style grills I was 2nd owner from 1974 till 2007. So my guess is that it is a typo #3600 maybe #1600 this type of statement in the guide was to tell people that during this build time 1447 to 1600 you could see 1st style or 2nd or both on a car. I know the grills were never changed on my car and there was no damage from 1974 on in this area. Also the first owner purchased the car in Aug 1971 and the car was built Sept 1970 and had no damage when he purchased it. Paul

[Richard T.]

Re: 1971-1972 Side Grille Differences

My name is Rich Taylor and I am a new member of the NCRS. I bought a 67 Corvette coupe in 67, ya it is gone, sold it, darn, and I have been into restoring cars for shows and fun for many years, early Ford V-8's, Chevrolet's etc. I own a very early 1969 built 1970 Corvette coupe that has been factory signed and dated by the builders in white paint under the hood, the same marking paint you will see on the underside of early Corvettes. The car is a complete all numbers matching original with 38,000 miles. At a recent concours located in Palo Alto CA. some of the NCRS members were there at the show. My car won a second in its class 1968 to 1982 and I wanted to know what needed to be done to the car to increase the point count. Other than detailing some of the engine orange and chassis paint, the body paint is the big thing that has been done to the car restoration wise which involved a complete removel of the mulsanne blue and a perfect match and refinish of the exterior. All the chrome, doors and hood were removed during this process along with the original side grilles. The side grilles have two black upper cross point mounting screws with recessed cup type washers attached. The lower part of the grilles have a stud attached for nut and washer attachement. One of the things the NCRS members told me about is the verticals that should be painted body color. My car had the chrome showing by mistake on the verticals. The week after the show, I removed my grilles and painted the verticals. Your picture shows what looks to be a silver or gray grille. Your grilles can be repainted with no chrome showing at all if you repaint your car to the factory color. GM did not bother to show the chrome on silver and gray Corvettes. Most cars you see today that show the chrome edges, have been repainted and the owners like the chrome showing. I would think you could go either way on yours and not get a point deduction.

[Thomas H.]

Re: 1971-1972 Side Grille Differences

Jeremy,

Picture of the side grill from my 71 LS5. Sept '70 build SN 1632.


Tom

[Warren F.]

Re: 1971-1972 Side Grille Differences

Jeremy,

Those ridges are actually a stepped ledge. They are on the bottom and the top underside. The 1971 grilles are actually styled in design that closely matches the front grilles, which have the stepped ledge on all four inside walls.

I believe the re-design of the side grilles was intentional for two reasons. First to allow more underhood heat or trapped incoming air to escape thru the side vents easier. If you look at a '70 style grille you will notice that the inset 3 sided cube extends much further inward, with less ability for air escapement. Second I believe it was intentionally re-designed to match the front grille styling, having both raised edges with chrome plating and the stepped ledge for aesthetics.

[Jeremy D.]

Re: 1971-1972 Side Grille Differences

Thanks to everyone who's replied....I'm pretty convinced that my grilles are the originals. They match the Steel Cities Gray paint perfectly, by that I mean that the wear, fading, condition, etc. perfectly matches the rest of the car. They don't look at all like they were repainted or touched up. I doubt the mounting screws have had a screwdriver in them since they were installed. Until someone proves otherwise, I'm going with the belief that mine are original to the car. I know the TIMJ is just a "reference" and should be taken lightly at times, but the bottom line is that we all want to know what's right and what's wrong with our cars before we stick them out on a judging field, and the TIMJ is a great tool for that. For me, I just want to make sure I have what I believe it is I have...Warren, I never realized it until your posts about that stepped ledge coinciding with the front grilles....it all makes sense. I learned something new today....thanks! Tom's picture is interesting...from the pic it looks like that's a '70 grille to me. The outer edges don't have that "lip" that the later ones do. But his is a really early car, so it would make sense too.
Just for kicks, and I'm not going to take mine off to see, but is there any kind of dating on the inside of these grilles?

[Warren F.]

Re: 1971-1972 Side Grille Differences

Yes. There is a casting clock symbol and the two digit year, ie 70, 71, 72.


Also here's another bit of information. The pot metal square bezels that frame the exhaust tips, are also dated in the inside rolled lip. They have the casting #/ part # and the two digit year as well. Lots of those have been changed out due to pitting caused by exhaust fumes. However if your wanting correctness you should check those as well.

[Thomas H.]

Re: 1971-1972 Side Grille Differences

Jeremy,

My car, being an early Sept '70 build, is a mix of 70 (left over parts I assume) and 71 parts. Interesting stuff when you start digging into it!

Tom

[Warren F.]

Re: 1971-1972 Side Grille Differences

Tom,


I have a friend who has a 1970 LS5, vin is 00504. I found him original exhaust bezels with the year 69 casted in. Those early ones are very tough to come across.