SURVEY: 1966 Engine Suffix Stickers

[Jack M.]

In the past, I've posted these GM photos of a 1966 Corvette body drop image from September 28, 1965.
Zoomed in, we could clearly observe the 'HT' suffix stickers on the HEAD (they appear to be individual stickers).
1966-Corvette-Body-Drop-(9-28-65)-01.jpg
1966-Corvette-Body-Drop-(9-28-65)-04b.jpg


In a conversation with Mark Nagy, he prompted me to re-scan an image from a 1966 Corvette News article (Vol 9 - #5).
The article went into depth, discussing 'Building the 427'... I've posted that PDF previously, but will attach a copy below.
Looking at the big block engines on the shipping rack, they also appear to have some suffix code stickers on the HEAD.
Unfortunately, the image was small/poor quality to begin with, so we can't ascertain the actual suffix codes.
(NOTE: The rack has 'IG' written on the left side... that would indicate a 396 with PG, but we see bellhousings.)
1966 Corvette News-01.jpg
1966 Corvette News-02.jpg


I also reviewed many magazine images, and early road test articles that covered the 1966 Corvette...
Although there were just a couple that included the back of the valve cover, none displayed an engine suffix sticker.
Zoomed in on the 2nd image, I don't see any evidence of where one would normally observe the top of the suffix sticker.
1966-L72-Corvette-Engine-01.jpg
1966-L72-Corvette-Engine-02.jpg


There have been reports of several early 427 engines using a BLACK air filter lid, with NO horsepower rating...
And we can clearly see the back of the valve cover, without the typical suffix engine code sticker(s).
1966_Motor_Trend.jpg


In previous years, we are aware that the engine suffix code was hand written on the head with a crayon/chalk.
The usage of new suffix stickers, could easily have been placed in the same location... likely at the start of production.
It seems we now have fairly undeniable reference, from multiple sources... covering both 1966 small blocks, and big blocks.

At some point during the 1966 production year, the sticker(s) transitioned to the valve cover...
So if you have an ORIGINAL

[Patrick H.]

Re: SURVEY: 1966 Engine Suffix Stickers

Jack,

One tip from studying these on early C3 Corvettes -

By now, the stickers are likely gone no matter where they were placed. Owners should look for adhesive residue, or dirt in a rectangle suggesting where the sticker used to live.

[Tony S.]

Re: SURVEY: 1966 Engine Suffix Stickers

I'm not sure this helps, but in 1965, the two letter suffix code was hand-written on the back of each head...not valve cover.

[Jack M.]

Re: SURVEY: 1966 Engine Suffix Stickers

Jack,

One tip from studying these on early C3 Corvettes -

By now, the stickers are likely gone no matter where they were placed. Owners should look for adhesive residue, or dirt in a rectangle suggesting where the sticker used to live.

THANX for the reminder, Patrick... it would be similar to the possible glue residue from the early 66 fan shroud stickers (that nobody mentions).
I had theorized that the engine suffix stickers were either moved from the head, to the valve cover location, due to heat issues...
Or it could have simply been an easier 'visual' check, when the stickers were placed in a higher position on the engine.
Unfortunately, we may never know... as this seemz to be another topic that has fallen into a proverbial 'black hole'.

[Jack M.]

Re: SURVEY: 1966 Engine Suffix Stickers

I'm not sure this helps, but in 1965, the two letter suffix code was hand-written on the back of each head...not valve cover.

Correct, Tony... I believe I did mention that already (as it was seemingly a larger/easier surface to write on).

[Patrick H.]

Re: SURVEY: 1966 Engine Suffix Stickers

I suspect that the roughness of the head didn't give enough net surface area for anything to stick, and that affected them more than heat.
The stickers only had to make it from Flint to the installation plant, and if they were falling off in that short period of time it's an issue.

[Jack M.]

Re: SURVEY: 1966 Engine Suffix Stickers

Valid point for a location change... but I'm mainly looking for placement confirmation, from our 66 owners.

BTW- I'm not very knowledgeable about the C3 location of suffix stickers...
I've seen something in a photo that seemed fairly odd, so I'll send you an email.

[Thomas N.]

Re: SURVEY: 1966 Engine Suffix Stickers

Jack
I do have the issue of that Corvette news, and the detail from the magazine isn't any better than the scan. One other thing, if you look at the picture closely and under magnification, the engine on the bottom row, to the left of the fork truck front tire does not have a decal at all.

[Jack M.]

Re: SURVEY: 1966 Engine Suffix Stickers

For those unaware, that magazine photo is a halftone image... a series of varying sized 'dots', that get more pronounced when you blow them up or use a magnifying glass. In my 1200dpi scan and working in Photoshop, I've attempted to fill in the area between the dots. Lotza work, but it really didn't help too much.

Tom's observation seems spot on... the question is, why? Was that suffix sticker omitted... did it possibly fall off... was it somehow placed elsewhere? It really doesn't change the facts from the images I've presented... and I was attempting to omit some additional images, as they mainly reflected the C3 generation.

But since a similar topic was broached... these are the photos I sent to Patrick today. Itz a reported GM photo from 1970, showcasing inbound engines for truck assembly. Zoomed in, I've noted a suffix sticker on the FRONT of a valve cover (with a 'can' still on the water pump, after transit). Does this indicate more suffix sticker inconsistencies? I'm just pointing out, what we all are observing.
Engines - Flint Engine Plant 1970 (inbound for truck assembly)-800.jpg
Engines - Flint Engine Plant 1970 (inbound for truck assembly)-ZOOMED.jpg