66-67 427 radiator shroud

[Ronald L.]

[E S.]

Re: 66-67 427 radiator shroud

IMG_20200731_162214443.jpgIMG_20200731_161440271.jpgIMG_20200731_161512088.jpgHi-pic.#1 of rivet is from the 66 TIMJ-(page 173, C5-10). pic.#2 is from 66 vin#37xx. Rivet is is clearly visible in both pics; and appears identical to me-May be we could learn approx vin# of the TIMJG car? All info. is valuable-correct? Pic. #3-from 66 vin.#37xx- Does that look like a "painted over " label?

[Tom D.]

Re: 66-67 427 radiator shroud

Adding photo of the top, for this same car.

top o shroud - 1.jpg

[ATTACH=CONFIG]100221[/ATTACH][ATTACH=CONFIG]100222[/ATTACH]
Left side looks like it has two holes filled or partially filled with bonding agent / goop. I don't see this as a rivet.
Second photo is the right side joint. 1967 390 HP 427 in car number 11532. Made in STL. Less than 26,000 miles since.

[Mark M.]

Re: 66-67 427 radiator shroud

E J, nice shots of what I'm seeing. Tom in top picture of shroud top of response 13, that is the 68 style shroud. There's a lot of them on c2s. Thanks guys.

[Ronald L.]

Re: 66-67 427 radiator shroud

Joe "Ditto"

You bring up a very good point.

It would seem in this thread that some here think the 68 shroud versions are original - and they are not.

Mark - you need to take a look.

the 66 shroud is NOT the same as a 67

and the 67 is no way even near the 68 tho as the guys mention....there are a lot of 68 shrouds with these rivets in mid year big block cars.

In my experience I have never seen a stock original fan shroud on a 65-67 that had rivets in them! But every 65-67 replacement from GM had the rivets in them.
That should bring out all the "Mine is original because I bought it from the original owner guys".
Sorry,

JR

[Jeff M.]

Re: 66-67 427 radiator shroud

My early January build 67 427 is black glass under paint and does not have a rivet. It is the original shroud. Hope this helps. Jeff

[Tony S.]

Re: 66-67 427 radiator shroud

Mark, I think that rivet is a "may" and not "shall". Tony

[E S.]

Re: 66-67 427 radiator shroud

Hi- The NCRS 1966 Corvette Technical Information Manual and Judging Guide (6th edition; page 173-picture C5-10) clearly shows the "single flat head rivet",and further states: A factory "fix" was to reinforce the upper left bonding with the use of a single flat head rivet.
The TIMJG does not indicate what the problem was, but I guess we can assume that the original bonding method was not satisfactory.
Anyway- the factory must have recognized and solved the problem early in production, as I have an "early " car (37xx) that has the rivet, and I believe it is original.
Some on this post seem to indicate that any 66 or 67 shroud that has a rivet is the result of damage or repair.
I would like to know if anyone out there has a 66 with an original shroud that does NOT have a rivet?
How did St. Louis deal with the problem for 67?
Better bonding agent??

[Ronald L.]

Re: 66-67 427 radiator shroud

EJ
please stop making this the norm, it was not.
I had vin 6xxx no rivet, have a 20xxx vin no rivet and I have or have had 30 (1966 1967 combined) big block fan shrouds as they are VERY different - not-one...ningino nada zero cero zippo ---none of them have the rivet. N-O-N-E.

If you were in the business at GM with body panels and I was, just a decade later, surface cleanliness and release agents could interfere with bond quality.
Could doesn't mean put rivets everywhere just in case it rains.
Guys - if you got a rivet - ok

If you are restoring - skip the headache and leave it alone no rivet.


The rivet was an in factory Repair Process ---- the exception guys ----- where the adhesion failed. This was a factory, for profit company and why would they pay to have someone sit at the end of line drilling and popping rivets, if it was not necessary? They would not. They didn't.

..... and half of the Big Blocks have a 1968 service shroud that never could have been built in 1966 nor 1967 sitting in front of the engine.

[Mike M.]

Re: 66-67 427 radiator shroud

i had a pair of 66 425's and three 67 big blocks, and none had a rivet in their shrouds. mike

[Wayne G.]

Re: 66-67 427 radiator shroud

My '66 427/425 vin#80XX built Dec.9'65 does not have the rivet on the shroud. I've owned the car since '76, never any front end damage, 99% original parts on the car.

Wayne

[Mark M.]

Re: 66-67 427 radiator shroud

Hey Ron, You said the 66 427 shroud is different than the 67 427 shroud! The ones I have here, grey or black all have the same molded shapes in all 3 parts. Only difference is the color or a rivet. The 67 427 cars we all agree have never been seen with a rivet yet.I have a few 68 shrouds and all 3 molded shapes are different than 66-67 though the assembly fits a c2 as we've seen on many cars. The 66 427 cars I've seen look like the same molded shapes as 67 but the fiberglass is grey and I've noticed these with the rivet. What are the 66-67 differences you've noticed? Considering the added input from members, I now believe many, 66's came without a rivet. Maybe the majority but there are a lot of them with the rivet and can't be discounted. The more 66 427 owners with original shrouds helping here, the more we'll know. I've been very busy and have to go out of town but I hope to post some pictures soon. Thanks all

[Jack M.]

Re: 66-67 427 radiator shroud

Mark- Back in post #11, I mentioned there might be some 1966-67 shroud differences, that you may be overlooking.
The AIMs call for different part numbers on the right side pieces, but I have no idea what the exact change entailed.

1966-BB-Shroud.jpg

1967-BB-Shroud.jpg

[E S.]

Re: 66-67 427 radiator shroud

Interesting- The AIM only illustrates to bond the upper R/H seam, and the lower middle seam- but not the upper L/H seam (the rivet location)?
Again-The 66 TIMJG states "A factory fix was to reinforce the upper left joint-bonding with the use of a single flat head rivet."
The 66 TIMJG goes on to state: "The top R/H side of the shroud is straight across, NOT cut at an angle as with later models."
These features,as well as the rivet,are clearly shown on page 173,picture C5-10 of the TIMJG.

[Ronald L.]

Re: 66-67 427 radiator shroud

Ed - forget it - the judging giude was written 50 years after the fact and too many times it fails to incorporate what is really seen on BENCHMARK cars, like cars with 11,000 miles - with their original tires, not General Jet airs, but real tires that were really installed in St Louis on Corvettes, cars that look brand new, bolt heads never been touched with a wrench - which if you are a forensic detective, you can spot a mile away.

The JG is a guide - it is NOT the Bible and is flawed. If your shroud is really a 66 with no rivet, leave it alone.

Remember the rivet was a R-E-P-A-I-R Process - nothing more. Why are you so emphatic to push this small point?
What's the hidden agenda?
Are you going to show on the market with a repro?

The shroud differences were posted about 10 years ago on this forum. Largely as Jack points out by posting part numbers and AIM detail, and I have written before, passenger side was changed, clearance to the lower rad hose.

Service parts from 1966 only existed until the mold was chamged in August 1966 for the SOP 1967, after that date, 427 shrouds made for the GMPD service parts were only available as the 67 version, and...1967 summer saw the same event repeated, the molds in many ways for 1968, and that part is the one too many have and think its original, funny thing is, its shifted 1" off center and if you were to mount it with out modification and started your mid-year BB engine, you'd hear some wonderful clanking and see a little flying fiber glass.