arcticcatmatt

Well the motor is out of my 71.. I am calling this mystery motor because its history is 100% unknown. Trying to figure out what I have here
The block casting is GM 3970010 .. the date code on it looks like "A 73 1". I looked where you find the partial VIN stuff and I don't get what I am looking at. I posted pictures below. My cars vin is 194371S107548
Any help would be appreciated! First time for me doing this
The numbers in the heads are 3973487 which a google search tells me 75cc.. but I don't know if these are the heads that would have came on a 71 or? The motor is going to be taken apart in coming days to see what is in there and get rebuilt if possible. Just want to make sure I am doing this right for my setup (small blower)
I flipped one of the photos

wan2run

The engine code is typically 3 digits, is that V01?

Maybe this will help - http://www.nastyz28.com/chevy-engine-code-stampings.php

Mike Ward

Is there a pic somewhere?

Bric

This is what I got from the Nasty Z site listed above. Take it with a grain of salt..... HTH

V = Flint
01 = January

30 = 30th of January (stamping is light may not be right number)

CGP = 1971, 350, m/t, 4 spd, Vin-LT1, 330 hp, 4bbl, Z-28

arcticcatmatt

I can clearly read the CGP which searching on google shows that is an RPO code and I found a camaro engine code site that says
CGP 1971 350 330 4 m/t, 4 spd

The date code doesn't really make sense. A camaro site says
A= January
73 = Day of month (what the heck)
1 = Last number of the year.. 1971

According to my vin number of my car.. it has a 'birthday' of Jan 25 1971

So maybe I have a January 1971 Camaro motor in my January 1971 Corvette?

The heads casting says 1968-1973 76cc's. One website says they were on 71-72 LT1 engines hmm

EDIT - You guys were responding as I was typing this.. thanks for that link! So it appears this motor is from the same date as my cars birthday but the vin doesn't match.. how strange!

Yep I think you got it BRIC. It appears that this motor is a 330 hp motor from a Camaro (Z28?) from almost the exact same born on date as my car. How weird is that? Wondering if thats a good thing or bad thing (rebuild or? ). My car is an original M/T 4 speed too, just like its saying about this camaro motor

Mike Ward

I can see your pics now- Firefox blocks your pics, Chrome does not (?)

Probably the casting date is A 13 1 which would be Jan 13 1971. Looks like the engine was originally in a Z28 Camaro- who knows how it ended up in your Corvette. Not factory.

7T1vette

Not assembled to a vehicle in the Corvette factory, anyway. Of course, the Z-28 engines and LT-1 engines were built in common engine factories, so they should be 'brothers'.

Deborah McKnight

what you have is a marine engine. check for a tag or the remains of, on the pass. side by the trans mounting area. mine was a mercury marine 350

bashcraft

What makes you think it's a marine engine?

restoman1

I respectfully disagree. Marine engines don't have partial VIN's stamped on them. In this case, the partial VIN (appears to be 1N521669) is from a 1971 Camaro assembled at the Norwood, Ohio plant. And as Brian and Matt have stated above, CGP is for a 350/330 with manual transmission from a 1971 Z28. I also think Mike got the casting date right. It's probably A131, or January 13th, 1971 which is a nice fit for the assembly date of January 30th, 1971.

Ed

73sbvert

I think it's possible that it IS a factory install, but the engine was sent to the wrong assembly plant for installation in the car. All the engines were made on the same line, then crated and sent to their respective car plants, correct?

This one was probably just sent to the wrong plant, and considering all the other F'k ups that the plants made during the 70's, they probably just installed it anyway, and overlooked the paperwork.

The 2 date codes being so close together suggests this, that it was probably not a motor change out, because I think it would have been WAY too difficult to find another motor so close to the original build date. Luck maybe...

LongIsland C3

It's funny that I stumbled across this post. A few years ago a friend of mine had the same mystery with a 72. After a LOT of digging (and luck) it turned out that the non-original engine was installed at the dealership under warranty.

restoman1

Yes, it IS a factory install, but installed in a 1971 Camaro. The VIN was gang stamped at the car assembly plant, not the engine assembly plant, so this particular engine was originally installed in a Norwood built Camaro. HERE'S a great article from John Hinckley regarding the first generation Camaro assembly process. Not exactly the same for the Corvette, but similar.

That's a little different. A warranty engine would have a CE number stamped on it indicating a service replacement "Chevrolet Engine". More info on service replacements HERE.

Ed

bmans vette

Either way the 3970010 if it is a 4 bolt main is a rock solid good block to work with.

It is the hi-nickel content block form the 70's.
I have 2 right now that are being made into 383 strokers - one for my truck to haul my boat and the other for my 75 Vette to haul azz.

Good luck with what you decide to do with it.

Bman

arcticcatmatt

Engine rebuilt and improved!



Rebuilt by Precision Crankworks in Windsor/Kirkwood NY. I hear nothing but great things about that place so I decided to go there. Tomorrow the motor is going back in the car.
Rebuild details -
The motor had forged TRW pistons in it, stock rods, stock heavy duty forged crank. The crank bearings were worn and dated 1992. The valves were worn. The headgasket was about to blow (few close spots). Cam was a B&M street challenger mild blower cam. Roller rockers, 4 bolt main.
Rebuild included -
Labor -
Hot tank
Bore to .040 over (was .030 over)
install new cam bearings and soft plugs
Grind crank R.020 M.020
Balance crank and rotating assembly
Press pistons on rods
3 angle valve job
Helicoil exhaust bolt hole in one head
assemble motor
Parts -
.040 over Forged TRW pistons (flat top)
.040 over moly rings
6 quart oil pan with side drain
High volume oil pump and pickup
.020 rod/main bearings
5.7 Scat forged rods
Roller timing chain/gear set
HP gasket set
2.02/1.6 valves/springs/seals
Cam bearings/Soft plugs
Oil/Filter/new braided oil pressure line
Paint

Now that everything in it is forged, I am going to increase my boost by 2 lbs.. have to figure out what pully to order. Thanks to everyone for helping me figure out what the motor is/was! I did get a message and phone call from someone that saw my post here and he wanted the motor for his 71 Z28 camaro since this is what it came out of.. but we couldn't agree on price. Only way I could have let this motor go was if he ordered me the 383 blueprint crate motor as my car is sitting in a mechanics shop taking up space waiting for a motor.

Thanks again!

Easy Mike

Looks good. Who picked it up and put it in the truck?

arcticcatmatt

^ Thanks! Was harder getting it out. 3 guys picked it up and carried it to some tires for it to sit on while they went and got the engine crane lol. Couldn't use the engine pallet because the oil filter hit it

Solid LT1

Guy with the Camaro is an IDIOT! Not too often that you relocate original motor. Shame you couldn't come to terms and swap.

Mike Ward

On the other hand, the OP could be considered to be greedy and an opportunist since to him it was just another block. A fair price would have been the cost of another 0010 block plus whatever unrecoverable money he had already sunk into it at the time. If the engine was already completed when he was contacted then ignore my comments.

arcticcatmatt

^ Yes. Engine was already done by the time I was contacted and my car is in a mechanics shop waiting for it. My only option was a crate motor with forged internals.. blueprint has one for $5,300. I offered him my rebuilt motor if he were to order me up the blueprint motor asap so I could give it to the mechanic to install.. he declined. It is the only option I had. I had to pay lots of money to get it rebuilt well and I have my car sitting in a mechanics bay for the last 2 weeks taking up space waiting for a motor.