martaroony

G'Day Fellas, Thought Id throw this one out there and see if I could get an education on what Looks to be a factory work around.

I'm just in the process of removing my TH400 to give it a detail , but also do a rear main seal on the engine, and on removing the exhaust and starter motor have noticed firstly, this cut around in the floor pan , that is most likely factory from the age and look of it , but boy does it look some what amateur-ish in its finish and appearance.
There looks to be a factory piece that is glued in place to give the tunnel a little more room , but the centre of this is also filled with a body filler of some sort, which looks to have been worked into place top to bottom with a scraper whilst it was wet, but they are all in keeping with the consistency of the rest of the sealer they have used on the rest of the joins in the floor pan.
I'm just wondering if this is just another early 67-68 C3 work around thing, and if anyone else has noticed a similar thing on their 67 C3.



Also, whilst removing the starter , I noticed these stampings on the block Pad under the starter motor mounting , can anyone shed some light on the reference these numbers might hold.
My first guess was perhaps TO for Towanda. ? Just a stab.....!




Thanks guys for reading this far, and for any input you might have to add.
Marty.

Mooser

I know that recessed patch panel was used on the 72 w/auto trans so was probably also on the earlier ones for the same reason.
M

Mines slightly more refined that that, doesn't have the wads of glass smeared over it but more or less the same

gbvette62

The relief was added to the passenger side floor of all cars with the Turbo 400, from 68 through at least 72, and maybe up to 75. The floors were redesigned, and also changed to sheet metal, in 76.

Easy Mike

It's not a work around.

All TH400 car got this bump out; manual trans floor pans do not clear the TH400; this bump out (it's factory) clears the tranny.

The underbody is not an appearance area and workers were not required to make it pretty.

The assembly instruction manual (AIM) shows the installation of this piece and gives instructions on how the original floor pan was cut to accomodate it. Check the M40 sections in Options. While in the AIM, make note of how the stock manual trans shifter hole is enlarged in order to fit the AT shifter, boots, and cable routing, etc.

I don't know whether 67s used the bump out. Floor pans and transmissoins were completely different for the C2s.

I agree it looks like a partial engine identification stamp, but do not have a clue why it would be near the starter. Just curious, but does the T0I8 match the number on the engine pad?

bkvette3

Hello Marty. Pretty sure my early model '68 looks exactly the same. I will check and post pics when I get back home from the family vacation. Cheers. BK3

martaroony

Thanks fellas , for your advise so far.

bkvette , Ill eagerly await your return to see if yours is the same ,

This looks as though the factory fit piece that is glued in after the corner has been cut off , has also had the center cut out of it for some reason , and then had a piece glued in behind it , then filled from the front and smoothed off as best with a spatula or scraper whilst it was still workable or soft.

All the filler ( glue) seems to be of the same consistency and colour to suggest that it was all done at the same time in the factory.

Question:

Can anyone tell me if the TH400 was the only tranny they offered for both BB cars and SB cars. ??????

Marty,

bkvette3

Hello again, Marty. I am pretty sure the TH400 was the only automatic available for the '68 Vette (BB or SB). Anybody correct me if I am wrong. I also believe 1968 was the first year for the TH400 in a Vette - replaced the 2 speed Powerglide found in the previous 1967 model. At any rate - I love the TH400 - very reliable transmission. BK3

martaroony

Hey Mike thanks for that, I raced straight into the Study , grabbed the Manual, and sure enough, (Drawing A14) , It never ceases to amaze me the detail in that AIM.
Just the very things I think "Nah, that wont be in there."
The drawing is a little hard to get a defining answer about the centre being cut out , But on close inspection , it does look as if there is 3 outlines of the replacement piece,
1st line being the outside Perimeter,
2nd line being the 1'1/2'' raised flange to glue to,
and 3rd line could be the centre cut out.
Suggesting that the centre is removed , for what ever reason , I don't know.


My thoughts were that this was either TO then 18, perhaps for a line of production, at the Towanda Plant.

OR;

T with 018 , as in a production date, in this case, would this indicate Jan 8th, or August 1st.
I think you guys in the U.S do, month /day, for your dates.


Anyone who can shed some light on this number would be great, It is located on the block machined surface, under where the starter motor would mount up.

Thanks Marty.

martaroony

I think your right BK, I found the drawings in the AIM pointed out by Mike, and they show the TH400 mounted up to either a 327 and 427.
I think the TH400 is to auto's , what the Top loader is to Manuals.
Iconic, and well designed.

So, I've answered my own question.

gbvette62

The Turbo 400 was the only automatic used with both small block and big block Corvettes, until the late 70's. There was also a beefier version of the TH400, for use with the 427/435, the L-88, and I think the LS-6.

Later Corvettes used the TH350 with the base L-48, and the TH400, behind the L-82.

I'm not sure what to make of the "T018". If it's a variation of the engine stamping, the "T" would be Tonawanda, and the "018" would likely be, January 8th. I've never heard of a V8 engine stamp, being anywhere but on the stamp pad. There's a pad on the left of the block, next to the oil filter, but it was used as an alternative position for the VIN derivative, not the engine suffix.

What's stamped on the engine stamp pad, and what's the engine casting date? These might help make some sense of the other stamping.

martaroony

Hey Thanks for that gbvette, Where about's is this other pad, you speak of, next to the oil filler.?
Do you mean the oil filler in the Passengers side rocker cover, if so is it directly down under the head ??

Do you know how far back the 3916321 400hp block was used ?

Was it used in C2's as well , or only at the start of C3's. ??

gbvette62

You misread my post. The alternate location is on the left (driver's) side, next to the oil filter, not filler.

It's a horizontal machined pad, on the flange that the bellhousing bolts up to. It's besides the oil filter, and in the same area as the clutch crossbar pivot ball attaches at. The Corvette plant in St. Louis, didn't use this pad, for the VIN derivative, but other plants did. I have a customer with a 69 Z-28, built at Norwood, OH, and his VIN is on the horizontal pad, by the filter. I've also seen a few Chevelles, using this alternate VIN location.

martaroony

Hehehe. Sorry mate. I've got to start wearing my glasses. I just figure if I dont wear them, then I'm not getting any older, the fact that I have them doesnt count.
Any how , I'll check around that area this afternoon.
Thanks. Marty.

Easy Mike

Might be nothing more than a worker playing with a gang stamp at Tonawanda.

The 321 block may have been used in the Corvette very late in 67 production.

Good reading here:


This is reasonably good:

martaroony

Hey mike.. thanks for that...
That brings me to a subject I've been meaning to ask on the forum.
Ive been wanting to buy a fairly comprehensive book on C3's . Spacifically 68 if I can.
Would you say the first book you referenced would be the best around for checking things like correct shock absorber colours and stickers.? And general correctness. ( If thats a word)
Or is there another that you would recommend...
Thanks Marty..

0Corvettes by George

The stampings at the starter pad were used on the "extra" blocks that were cast and finished but not meant to be installed on the production line.

These stampings are found on "Over The Counter" blocks, and on factory and dealer replacement engines.

Additionally, these blocks were generally "pulled" from one "casting run" on the same day, resulting in several blocks with the same stamping.

G.

Easy Mike

There isn't one specifically for 68s. Rick Bizzoco's 1969 Corvette Guidebook is good but is 69 specific. Just the same, there is a pretty good amount of 68 carry over.

Yes and the NCRS 68-69 Judging Guide...and any other good reference you can your hands on.

martaroony

Thanks 1960fi, that's really interesting.
Can I ask how you know this , have you had any experience with these engines yourself ?

This is why this forum is worth its weight in gold, Gentleman like Mike and 1960fi , willing to share their vast knowledge..

Marty..

martaroony

Mike , I found the book you recommended on Fleabay, Just about fell over backwards when I saw the Price.

http://www.ebay.com/itm/Vette-Vues-Fact-Book-of-the-1968-1972-Stingray-by-M-F-Dobbins-1991-4e-SC-/190880681084?pt=US_Nonfiction_Book&hash=item2c71600c7c
Can you believe it .

Have found a more reasonable issue new for $60.00.

Marty.

Easy Mike

Dr. Dobbins' books are still in print. A $250 asking price on eBay is ridiculous.