help decipher my 69 Nova

[racerkvn]

Originally Posted by GMC_Typhoon

As far as I know you can only not get air conditioning on the solid lifter motors. So I don't think it would be any problem to get air on a low horse big block.

That was my understanding as well.

[WILMASBOYL78]

Sounds like you have an interesting car there...the subject of a big block Nova equipped with factory a/c has been discussed here before. It is generally accepted that none were produced, sort of like the L89 option in a Nova.

Of course, many folks claim that GM did some one-off things for certain people, adding to the urban lore of these cars.

Without documentation it is hard to prove...but an expert inspection of the a/c install and other items might shed some light. If the car was converted, there will likely be evidence. The swapped trans also adds a little mystery to this car. The TH400 was standard behind the big blocks, and they were pretty much indestructible, so why bother to down grade to a TH350 ??

The cowl tag date of the car and the axle assembly date are very close, almost too close. The BL code doesn't make sense for a big block car...most L34 cars had a 3.31 or 3.55 axle.

Lastly, the engine stamp info makes no sense...a JM stamp on a 1969 '272' block, equates to a 396/375hp with aluminum heads with a TH400 installed in a Camaro. The correct code for an L34 Nova with TH400 is JI...so this adds another layer of doubt to the process.

So, my guess regarding this car is this: it was likely a factory small block car with a/c...that would help explain the TH350 and 3.07 axle. The big block was added at some point, perhaps during the restoration, and things were trimmed out to make it look like a factory 396 car. As for the deck stamp...without photos it is hard to confirm if it is authentic. If it is a real L89 block with low horse parts on top, it may be worth a lot to the right person.

Hope this helps...wilma

[racerkvn]

Originally Posted by WILMASBOYL78

Sounds like you have an interesting car there...the subject of a big block Nova equipped with factory a/c has been discussed here before. It is generally accepted that none were produced, sort of like the L89 option in a Nova.

Of course, many folks claim that GM did some one-off things for certain people, adding to the urban lore of these cars.

Without documentation it is hard to prove...but an expert inspection of the a/c install and other items might shed some light. If the car was converted, there will likely be evidence. The swapped trans also adds a little mystery to this car. The TH400 was standard behind the big blocks, and they were pretty much indestructible, so why bother to down grade to a TH350 ??

The cowl tag date of the car and the axle assembly date are very close, almost too close. The BL code doesn't make sense for a big block car...most L34 cars had a 3.31 or 3.55 axle.

Lastly, the engine stamp info makes no sense...a JM stamp on a 1969 '272' block, equates to a 396/375hp with aluminum heads with a TH400 installed in a Camaro. The correct code for an L34 Nova with TH400 is JI...so this adds another layer of doubt to the process.

So, my guess regarding this car is this: it was likely a factory small block car with a/c...that would help explain the TH350 and 3.07 axle. The big block was added at some point, perhaps during the restoration, and things were trimmed out to make it look like a factory 396 car. As for the deck stamp...without photos it is hard to confirm if it is authentic. If it is a real L89 block with low horse parts on top, it may be worth a lot to the right person.

Hope this helps...wilma

I know without documentation it can be argued back and forth all day. I was sure hopeful the build sheet was in the car but it at least wasn't under or behind the rear seat as I yanked that out to look for it. I didn't go any further looking though.

From all of my research (which isn't much in the grand scheme of you guys) everything you've said is right in line with everything I've read about too. I was fully expecting "JI" on the block and at first glance I thought it was JI but after cleaning the area some more and playing with different angles of lighting, it is definitely "T1106JM 19W353779". I will see if I can get a picture of it to turn out maybe tonight. I do have a picture that I took but I've doctored the picture so much to make the numbers standout that it really doesn't show an accurate depiction of what the stampings actually look like in person.

The Turbo 350 had me scratching my head too for the same thoughts as you, why would someone "downgrade" from a Turbo 400. You know, you bring up an interesting thought. I have been fixated on the big block because everything (minus the transmission and the questionable A/C) adds up to a factory big block car in terms of the big fuel line, dual exhaust mounts in the rear subframe, 5 leaf leaf springs, 12 bolt, etc. I didn't think about it going the other way of possibly being a small block A/C car that someone stuffed a big block into. That might actually be what is going on here. I say that because, man there is absolutely no indications of the sheet metal on the dash or the firewall being "massaged" and or messed with in regards to someone adding factory air components to a car that didn't have A/C to begin with. I would think if the body didn't originally have A/C there would be some signs of modifying something even as minute as possibly elongating screw holes or an opening somewhere but there is nothing that remotely seems tampered with or and/or cut.

I would love for someone who "knows" these cars to look it over because just the same, without documentation, it's still 50/50.

[WILMASBOYL78]

Originally Posted by racerkvn

I know without documentation it can be argued back and forth all day. I was sure hopeful the build sheet was in the car but it at least wasn't under or behind the rear seat as I yanked that out to look for it. I didn't go any further looking though.

From all of my research (which isn't much in the grand scheme of you guys) everything you've said is right in line with everything I've read about too. I was fully expecting "JI" on the block and at first glance I thought it was JI but after cleaning the area some more and playing with different angles of lighting, it is definitely "T1106JM 19W353779". I will see if I can get a picture of it to turn out maybe tonight. I do have a picture that I took but I've doctored the picture so much to make the numbers standout that it really doesn't show an accurate depiction of what the stampings actually look like in person.

The Turbo 350 had me scratching my head too for the same thoughts as you, why would someone "downgrade" from a Turbo 400. You know, you bring up an interesting thought. I have been fixated on the big block because everything (minus the transmission and the questionable A/C) adds up to a factory big block car in terms of the big fuel line, dual exhaust mounts in the rear subframe, 5 leaf leaf springs, 12 bolt, etc. I didn't think about it going the other way of possibly being a small block A/C car that someone stuffed a big block into. That might actually be what is going on here. I say that because, man there is absolutely no indications of the sheet metal on the dash or the firewall being "massaged" and or messed with in regards to someone adding factory air components to a car that didn't have A/C to begin with. I would think if the body didn't originally have A/C there would be some signs of modifying something even as minute as possibly elongating screw holes or an opening somewhere but there is nothing that remotely seems tampered with or and/or cut.

I would love for someone who "knows" these cars to look it over because just the same, without documentation, it's still 50/50.

Here are some additional things to consider: A small block car could have a 12 bolt rear, dual exhaust and multi-leaf rear springs. As for the fuel line...the 350/300hp small block used a dual fuel line setup, one being the return. Not sure if the lower hp versions had this, they may have been single lines. Regardless...the 3/8" fuel line could have been added easily during the resto.

Did you state the car is badged as an SS..?? Another item to look at is the transmission cross member...pretty sure the TH400 version is unique. I'll bet it has a TH350 crossmember...

Based on your assessment that the car has not been modified to accept the a/c system...it is really telling me this was a converted car. Does the engine block have the large plug by the oil filter?? This was unique to the high horse big blocks...you may have a 4 bolt block with low horse parts bolted on....or whoever stamped the motor didn't know what they were doing.

Why not post some photos of the car and re-take a good image of the deck stamp...the gang here can help sort this out for you. There may be an SYC member near you who could take a look.

-wilma

[racerkvn]

Originally Posted by wilmasboyl78

here are some additional things to consider: A small block car could have a 12 bolt rear, dual exhaust and multi-leaf rear springs. As for the fuel line...the 350/300hp small block used a dual fuel line setup, one being the return. Not sure if the lower hp versions had this, they may have been single lines. Regardless...the 3/8" fuel line could have been added easily during the resto.

Did you state the car is badged as an ss..?? Another item to look at is the transmission cross member...pretty sure the th400 version is unique. I'll bet it has a th350 crossmember...

Based on your assessment that the car has not been modified to accept the a/c system...it is really telling me this was a converted car. Does the engine block have the large plug by the oil filter?? This was unique to the high horse big blocks...you may have a 4 bolt block with low horse parts bolted on....or whoever stamped the motor didn't know what they were doing.

Why not post some photos of the car and re-take a good image of the deck stamp...the gang here can help sort this out for you. There may be an syc member near you who could take a look.

-wilma

Trying to see if the picture is attached, I apologize for the "dirty grime". It's been leaking oil since I got it but not bad enough to pull the motor out yet. And I drive the car regularly. It was late when we got home last night and I ran out to take these pictures.

[racerkvn]

I have zero'ed in on the conclusion that the car was originally a small block car with A/C and when it was "restored" somebody found a "correct 1969 L34 396" and put it in there. The car is extremely nice just not as unicorn'ish as I was beginning to believe once I started chasing the numbers. As I mentioned, I didn't buy the car under the impression that it was a numbers matching car but the more I looked into the numbers the more the excitement was building. I gotta send a huge THANK YOU to the guys who helped me (from this forum group but behind the scenes) decipher the numbers and figure this thing out! The only question remaining is, was it originally an SS small block car but at this point, it doesn't really matter. Now, knowing it's NOT the one and only documented 69 396 Nova WITH A/C in existence, I can move on to doing the things that I wanted to do to the car when I bought it! First thing I did after deciding it's just another 69 big block Nova, was buy some wheels! Because it is such a nicely restored car I'm not going to do anything that can't easily be reversed but slapping some wheels and tires on it definitely makes it MINE.

I did send off for the shipping dox from the NCRS and the car has a production date of November 15, 1968 (which coincides with all the dates on the car) and originally sold out of Ed Mollision Chevrolet in Birmingham, AL. I thought it was pretty neat to find out the car was an Alabama car and after going who knows where, it is BACK in Alabama.

[olredalert]

Originally Posted by WILMASBOYL78

Sounds like you have an interesting car there...the subject of a big block Nova equipped with factory a/c has been discussed here before. It is generally accepted that none were produced, sort of like the L89 option in a Nova.

Of course, many folks claim that GM did some one-off things for certain people, adding to the urban lore of these cars.

Without documentation it is hard to prove...but an expert inspection of the a/c install and other items might shed some light. If the car was converted, there will likely be evidence. The swapped trans also adds a little mystery to this car. The TH400 was standard behind the big blocks, and they were pretty much indestructible, so why bother to down grade to a TH350 ??

The cowl tag date of the car and the axle assembly date are very close, almost too close. The BL code doesn't make sense for a big block car...most L34 cars had a 3.31 or 3.55 axle.

Lastly, the engine stamp info makes no sense...a JM stamp on a 1969 '272' block, equates to a 396/375hp with aluminum heads with a TH400 installed in a Camaro. The correct code for an L34 Nova with TH400 is JI...so this adds another layer of doubt to the process.

So, my guess regarding this car is this: it was likely a factory small block car with a/c...that would help explain the TH350 and 3.07 axle. The big block was added at some point, perhaps during the restoration, and things were trimmed out to make it look like a factory 396 car. As for the deck stamp...without photos it is hard to confirm if it is authentic. If it is a real L89 block with low horse parts on top, it may be worth a lot to the right person.

Hope this helps...wilma

--- It had an open rear end, so no one was thinking drag racing, or anything close. Don't exactly know what the ordering customer was going for....Bill S