1961 Corvette engine date code and stamp pad
The broach marks definitely run front to back. I used some thinner and a scotchbrite pad to clean the paint off, so there may be some streaking from rubbing it up and down the pad.
The stamp pad on the block reads F09I9DG which is Sept 19th. That's 3 days after the 09/16/60 cast date if I'm reading everything correctly. I pulled the right side valve cover and found the date of the head to be 06/09/1960.
The 3774692 head was used only in 1960 and 61 and is correct all 230,245,250,270,275 and 290hp Corvettes. Intake valve was 1.72 size and exhaust was 1.50. The combustion chamber had 59.669 cc size.
The 3774692 head was used only in 1960 and 61 and is correct all 230,245,250,270,275 and 290hp Corvettes. Intake valve was 1.72 size and exhaust was 1.50. The combustion chamber had 59.669 cc size.
If one exhaust valve had an extra .005 taken off the face it might change that number to 59.701 cc.
Like this late '60 solid cam 270hp had...
Base cars used the copper/brass rad in '60.
1961 MY brought a new aluminum radiator with separate expansion tank into production. Being such a early car, your '61 was possibly allocated leftover stock from '60 inventory. That used in lieu of the new aluminum rad and separate expansion tank. Or of course it's possible it was changed to a top tanker later. Maybe because of that odd contraption on your upper rad hose. It has 2 vacuum lines going to it, almost like a valve to reduce or increase flow. Strange.
EDIT....I just figured out what it is. My wife's E-Type Jag has the same gadget. It's a thermostatic control valve. At a certain temperature, the vacuum valve opens or closes. Right rear head in this pic...
and thingy with the 4 vacuum hoses shooting up near the firewall(bulkhead in Jag talk)
C37430 in the below diagram. In the Jag, it was used to retard timing as part of the emissions system for fuel economy. The Jags had vacuum "retard" instead of vacuum "advance" distributors !!
Yours...
The hoses are heading back to the carb or distributor vacuum advance. It could be a vac control for the advance based on engine temperature.
On your top tank there's a Harrison label. When you get a moment check for a date code.
I'm only hoping it is still filled with anti-freeze. If so it may have saved it.
Last edited by rich5962; Aug 14, 2015 at 05:41 AM.





Not anyplace else, that i am aware of, mandated these. I would be highly surprised to find your Jag came with it from the factory.
Doug
Not anyplace else, that i am aware of, mandated these. I would be highly surprised to find your Jag came with it from the factory.
Doug
Next time I'm at my shop I'll look for the date code on the Harrison tag.
There is also this. A breather hose from the valve cover is cut into the intake manifold. You can see it enter the manifold through with what looks like a welded in fitting behind the carb.
Last edited by Randy G.; Aug 14, 2015 at 11:30 AM.
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Not anyplace else, that i am aware of, mandated these. I would be highly surprised to find your Jag came with it from the factory.
Doug
On the E v12 jags in 72-74, emissions equipment was required for all Canada & US Imports, up to engine numbers 7s8444, in 1973, when 2+2 production stopped. I imagine if it came to the US, it had to meet CA standards so all were built this way. 1974(last year of the e-type) open two seaters still required it. Part way through it also was required for Sweden and Japan and any other "EEC" countries.
This thermostatic vacuum system was such a nightmare, along with the GM air pump, gulp valve, vacuum retard unit, air rails on each side of the intake, solenoids and fittings, charcoal casister fuel system, etc and was one of the reasons for the demise of the e-type. It was no longer cost effective for Jaguar to continue the model. They went to the v12 in late '71 to maintain the previous xk 6 cylinder e's spec of being a 150mph capable road car. A few years later it was gone.
The wife's jag went through the judging process through JCNA many times. It actually lost some points years ago as it was missing some of the emissions hardware. I had to find it all and get it "visible" again for the last go around of judging back in '08 when we stopped entering. Not bragging, but.......that year her car got 99.615% average in national recognition, 1st place here in the SE Region, 4th place in North America.
Rich
p.s. I don't own it, I'm just the mechanic for the woman who owns it.
Last edited by rich5962; Aug 14, 2015 at 12:41 PM.

I think you have a legitimate stamp
Last edited by Frankie the Fink; Aug 14, 2015 at 03:38 PM.





I moved to CA in 1980 and was told I needed to install one of those radiator hose gizmos, and a draft tube eliminator to register my car in CA. I already had a PCV valve, but I refused to install the vac adv disconnect, so I didn't register my car in CA for long time, i just drove it on expired plates.
here is the story:
I bought my car in Helena, MT in 1974, it was wrecked in Blackfoot, ID in 1969,and sat in a junkyard in Helena in the intervening years.
During negotiations to buy the car, I noticed the VIN tag was on the door frame, attached with sheet metal screws . I asked the guy who I was buying it from if he thought the car was stolen (I knew the guy, it wasn't like he just rolled into town with 'Vettes for sale cheep). He said he didn't think so, but that steering column had been changed.
No problem, I bought the car, spent 6 months scraping up the money to buy a used engine and transmission for it and got it sort of running. I submitted the old Idaho title to MT DMV, and got registration and plates in 1974. Over the next 5 years, I restored the car to respectable appearance.
Fast forward to CA in 1980. When I went to register it there, I found out they wanted to retrofit it with smog devices, so I said to hell with that and just drove the car on expired MT license plates for 11 years until I found out they had they rescinded the smog retrofit rule some years earlier.
Knowing that I was now safe from smog devices, I went to the Fullerton, CA DMV to register the car in 1991. Going to a CA DMV office is not for the faint of heart, just getting past the gauntlet of Hari-Krishnas milling outside the doors soliciting donations takes the agility of a quarterback, or the brawn of a fullback, coupled with the diplomacy of George Steinbrenner.
After my turn of 40 minutes of waiting in boredom, I get to the counter, and present my Montana title and registration. She looks at it and asks why the registration has been expired for 11 years. I told her the car was in storage in Montana all that time. OK, no problems there, then says she has to inspect the car, and to bring in around front, which I did.
DMV Lady comes out, looks at the car (At that time is was a 97% Concourse show car, in the modified class, in other words, it was spotless inside and out, with 25 coats of nitrocellulose lacquer candy black cherry paint on the body;( I have literally have had several nubile young gals come up to me and ask if they could lick it. Unfortunately they were referring to the paint. ), she looks at the VIN tag and says "wait right here, don't leave" and runs inside. About 30 seconds later three big guys came running out, one with a wire brush in his hand and says: "You, outta the car, NOW, go stand against the wall".
Not quite knowing what was up, I get out and ask them what was wrong?
Sir, this car is probably stolen, the VIN tag has been removed and replaced, go stand against the wall, NOW (two big burly goons had now positioned themselves on either side of me, I think the Hillside Strangler got more assumption of innocence than I was getting at the time). Me: No, the steering column where the VIN tag usually resides has been replaced, so the tag was moved to the door jamb, the state of Montana didn't have a problem with the tag being moved.
So, one guy goes around the front of the car, fumbling under the grill for the hood latch. After watching him look for a latch in the grill area, and even crawl underneath the front of the car trying to figure out how to open the hood, he finally said to me:
"Open the hood, we will check the engine numbers"
So, I open the hood, and guy with the wire brush is all set to brush off inches of expected crud (you could see the gleam in his eye, and he literally was all ready leaning forward over the fender with wire brush in hand as the hood was being opened, ready to corral a dangerous criminal by proving the engine SN didn't match the body VIN), and after the shock of the rear opening hood wears off, he moves to the side of the car and sees a absolutely spotless Concourse engine, and his mouth drops open and he kind of looks back and forth at true spotlessness, with chrome, new paint, neatly arranged plug wires etc.. I then tell him that the engine number is supposed to be right there on the right front side of the block, but it is only a block code, they didn't serialize engines back then, plus I installed a new factory L79 crate engine back in 1976.
Well, now they then go inside, while demanding I still stay at the wall, all but spread eagle, while they go inside and confer, making comments about secret VIN code locations to them selves.
After about 10 minutes they come out, release me from my virtual prison at the wall, and they then tell me they can't register the car until they verify the ID, and that I need to call the CHP for that.
So, next day call the CHP and set up an appointment to go to their division in Orange, CA that does this stuff, and drive down there, and an officer whose name I can’t recall, so I will call him officer Smith, comes out and tells me to drive the car into a bay in the Chippie compound and then go wait in the front office.
I ask why is that?
Officer Smith replies: There are secret places where there are VIN codes on vehicles that we don't want known by the public.
I say, Oh, yeah, the one on this car is located on top of the frame, directly under the drivers seat. His jaw kind of dropped open. So much for their secret. Anyway, he made me go up front so they could confiscate the car if the numbers didn't match.
About 10 minutes later Officer Smith comes up front and tells me he can't read the number and that I was going to have to cut the floor pan out and bring the car back so they could read it.
I Said I ain't cutting the floor pan out. He says then you can't register it in CA until we verify the number; I say, but I am supposed to register it here, I am a Californian resident now; we went back and forth a few times, finally he says register it again in Montana.. I ask isn't that illegal since I now live in CA, he hems and haws and says yes, but, etc, etc.
I then ask him if I can raise the number to be visible, at my house, can he come out and look at it?
Officer Smith says yes he will come out to verify the serial number and gives me his card.
Driving straight home, I jack the car up get out some soapy water water, a scraper and wire brush and clean the top of the frame beneath the drivers seat. I get out a mirror and flash light out and BINGO, you can see the SN, and it matches the title (I was getting kinda worried about then, I wasn't sure if I was going to have to go on the lamb, sort of a Lost Dutchman existence, traveling from state to state, but never being able to register my car).
I promptly called up Officer Smith in case the serial number wanted to migrate or something in the next few hours and tell him I found it, and he comes out pronto in his black and white CHP Mustang, opens the trunk, pulls out and puts on his coveralls, crawls under there, and looks and says, "I can't see the whole number, but I can see the 9141 of the last digits and that is good enough for me".
So I ask him what now?
Officer Smith says bring the car on back and they will assign a new serial number and place a new CA VIN tag (In a real obnoxious place) on the car.
I ask: can't I use my old SN, and place your CA tag right below the Chev tag on the front of the doorjamb? Officer Smith says no, we have to place it where CA says it should be.
Knowing a California assigned VIN would be the Kiss of Death for the car, relegating it to a collectibility status somewhere between Dune Buggy, and Low Rider, I had to think of something.
OK, I had an idea; I went in and wrote a letter to his supervisor telling the supervisor how Officer Smith went out of his way, coming all the way out to my house to help me solve this insurmountable problem, when nobody else would, and how he was a credit to the CHP, etc, etc. I laid it on pretty thick; and took about 2 whole single spaced type written pages to lay it on thick. This letter was so good, that had I copied it to the appropriate people, Officer Smith would have been sleeping in the Lincoln Bedroom, been Knighted by the Queen, and considered for Beatification by the Pope.
The next week, I go down to the Orange, CA CHP station to get my CA tag VIN Cert applied to the car, and Officer Smith, comes out kind of grinning,( obviously his supervisor had shown him the letter I had written and placed it in his file), and says, here, we got your old serial number put on the CA VIN tag, where did you want it installed? OK, under the old one is fine, would you like to install it? Here is the drill and punch.
I declined to install it myself, let him put the tag on, right under the old one, where I pointed out that was where I wanted it..
Then I had to go back to DMV with the certification of VIN.
Going back the second time to that den on incompetence, sullenness and hostility was enough to make me want to find a bridge to jump off of, that seemed less painful. Surly employees, screaming litters of kids be herded by moms that spoke foreign languages, Hari Krishnas (called ISCON now), begging donations at the door; I felt like I was in the bar from Starwars, and wondered why the place couldn’t instead be full of single 20-something babes, waiting for 40 minutes like I was to get their car registered.
Now my number is called and I finally get to the registration counter and the lady asks how much I paid for the car? I said $500, here is the bill of sale. I produce the bill of sale, dated March 16, 1974, written in crayola on a 3" by 5" scrap of paper ( it was all we could find at the time, what can I say).
She looks at it and says, "this car is worth a lot more than that, how much is it worth? I say: I paid $500 for it, there is the bill of sale.
We went back and forth a while, and then she tells me I have to get it appraised before I can register it. I say: I ain't paying for it to be appraised, if you want it appraised, you can hire an appraiser and have him come to my house and appraise it".
I get a dirty look and she gets a supervisor and they start looking through blue books and valuation guides and then get more and more desperate, and are furiously throwing new and old Kelly Blue Books around trying to find a 1961 Corvette in them that just isn't listed, to prove the car is worth lots more so the grand State of California can extort me for more money (This was before the KBB old car guide) , and finally the supervisor asks me how much the car is worth? I tell him: I paid $500 for it, there is the bill of sale, if it has gone up or down, since then, I have no idea, all I know is I paid $500 for it. (Car was appraised shortly after for $35K).
He shakes his head in disgust and tells the gal to put down $500 as the value.
So, my registration in CA was $18 a year, instead of the $1000 a year they were hoping to get.
All over two sheetmetal screws holding the VIN tag on.
bastards. :-)
Post script: After I registered my Corvette in Arizona after my escape from California and permanent move here , the California DMV sent me a letter, to my Arizona address, demanding I reregister the car in California or they were going to seize the vehicle. My written reply was: “Bite Me”. Haven’t heard a thing from them since.
PS: maybe sometime I will relate the story on how the State of Ca, refunded me the sales tax on a Ferrari I bought....















