BSiegPaint

A member asked questions about a hood I had for sale, and I was completely unfamiliar with what he was asking, and still am, even after he shared pictures with me. So I thought I would put up some pics with the questions of what is right, what is year-specific, what am I missing, and what do you have...?
Lets start off with what I have and have had in the past. 1970 hood - the rear of the hood has open cut outs across the windshield edge. This hood and my '71 hood are the same. '71 on the left and '70 on the right:



Here is the first comparison on a hood - note the back of the hood has two flat panels that cover the cutouts:




Here is the last comparison - the back area has a pressed panel that fits the shaped area and covers it neatly:




I have to admit that I have never, ever noticed this before, and I can't say that I've seen a bunch of these panels lying around at swap meets. My hoods show no sign of having any piece tack welded in. Why would they have been removed?

Can anyone shed light on what these differences are and when they occurred? I'd like to have the right appearance under the hood when I get my '70 finished!

joe_padavano

I'm guessing that these differences are engineering changes over the production run. The top photo with the openings is consistent with what is under the vents on a metal hood, to allow airflow into the cowl box. Obviously the fiberglass hood doesn't use these. The second photo appears to be an interim fix, where flat plates were spot welded over the holes. Perhaps this was done to avoid a potential problem with the exposed underside of the fiberglass - I'm guessing here, but the high pressure at the base of the windshield might have caused a problem with the 'glass-to-metal bondline? (OK, I'm reaching for this one). The final photo appears to be the permanent fix to blank off the holes completely.

Eddie Hansen

Please let me know if I should start a new thread,
but noticing the air cleaner : flange" mounted to the hood, any thoughts of adding similar to a 69 hood using perhaps a portion of an aircleaner base and utilizing the 69 bolt on hurst scoop? I know stock they basically just cut a square hole but as I am using a corvette cowl induction air cleaner I was wondering if it is worth the effort? or just cut the hole and make sure the foam seals it? I think you could cut most of the base off (to bottom of air horn inlet perhaps and use it similar to the hood shown. Very much like what Chevrolet did with the chevelle and Camaro and the w-25 of course?

BSiegPaint

Joe, I'm sure you're right. It would be interesting to find any documents stating a reason for this engineering change. Heat buildup and paint issues? Glue/bonding, like you said? It would be nice to find out when this started and if it ran through the end of production. I'm now more confident that my hoods are as original as they need to be. I hope others will take the time to post up what they have and when their cars were built. My current '70 is missing its original hood, but I had an April '70 W-30 without this cover for sure - and I have a '70 and '71 hood in my garage that show no signs of being tampered with in this area.

BSiegPaint

The other thing to note is that hoods with the plates have a solid support across the back, and the ones without have a series of holes across that piece. I'm wondering if it was a wind noise issue....

joe_padavano

That also crossed my mind.

anthonyP

Does it possibly have anything to do with the hood changes that removed the rear vents on non-A/C cars starting in January 1972 or the required fender & hood crunch zones starting in January 1971?