Early 66 Big Block Expansion Tank and HP question

[Kenneth A.]

I have an August Production 66 427 car - matching number. The car was delivered in Denver and stayed there until 1971 where the same owner had the car for 33 years. It is now a 3 owner car and well cared for. The background is for the next question. The car has a Harrison expansion tank on the right side in the same place as my small block 66 had. I never thought twice about until the other day when a corvette expert told me that bb never had an expansion tank period. Although he also told me the hood support was on the wrong side and my seatbelts were 65s which I explained to him were both correct since my car was an August or early 66 he had never heard of that either. All the same the owner of 33 years stated the car looks just like it did when he got it in 1971 expansion tank and all. After all of this my question is who is right????

Also since my car was an early 66 model did aircleaner sticker say 427/390 or 427/425 as it was originally set up.

Thanks for any and all help

[Joe L.]

Re: Early 66 Big Block Expansion Tank and HP question

I have an August Production 66 427 car - matching number. The car was delivered in Denver and stayed there until 1971 where the same owner had the car for 33 years. It is now a 3 owner car and well cared for. The background is for the next question. The car has a Harrison expansion tank on the right side in the same place as my small block 66 had. I never thought twice about until the other day when a corvette expert told me that bb never had an expansion tank period. Although he also told me the hood support was on the wrong side and my seatbelts were 65s which I explained to him were both correct since my car was an August or early 66 he had never heard of that either. All the same the owner of 33 years stated the car looks just like it did when he got it in 1971 expansion tank and all. After all of this my question is who is right????

Also since my car was an early 66 model did aircleaner sticker say 427/390 or 427/425 as it was originally set up.

Thanks for any and all help

Kenneth-----


What radiator does the car have and do you know if it's original to the car.

It's possible that some very early 1966 with L-72 might have been built with the 1965 L-78 radiator system configuration. If so, they would have used an external supply tank as all 1965 L-78's did. Also, what is the date code on the supply tank.

Understand that I really don't have anything to support the notion that early 1966 L-72's might have been built with the 1965 L-78 radiator configuration, but I still consider it a possibility based upon a few "snippets" of things I've come across over the years.

[Steven S.]

Re: Early 66 Big Block Expansion Tank and HP question

Joe, although he didn't say specifically, it sounds like the car in question may be an L36. I thought at one time I read something about early L36 cars having been rated at 400, or maybe I imagined it, either way I never heard of anyone claiming they were rated at 425 initially.

It will be interesting to hear what radiator is in the car and if the items are dated in line with the cars build.

Steve

[Larry M.]

Re: Early 66 Big Block Expansion Tank and HP question

Early 1966 models cars should be 427/400 HP or 427/450 HP. This changed after a few months production.

The 1965 model 396 also had the battery on the drivers side and a cut-out door in the inner fender for access.

Where is the battery located? Also would be interested in the VIN, and what is stamped on the TRIM TAG? These may help decide. Could it actually be an early prototype or a pilot car?

Larry

[Kenneth A.]

Re: Early 66 Big Block Expansion Tank and HP question

Thanks for the clarification on the HP question.

The battery is on the passenger side as is the hood support. The expansion tank numbers are 3155416 and 65 M

VIN is 194376S103279

Trim Tag

Chevrolet
006

Style 66 437
Trim 418
Body A-O 622
Paint 980

[Wayne M.]

Re: Early 66 Big Block Expansion Tank and HP question

I have an August Production 66 427 car - matching number. .... The car has a Harrison expansion tank on the right side in the same place as my small block 66 had. I never thought twice about until the other day when a corvette expert told me that bb never had an expansion tank period. Although he also told me the hood support was on the wrong side and my seatbelts were 65s which I explained to him were both correct since my car was an August or early 66 he had never heard of that either. All the same the owner of 33 years stated the car looks just like it did when he got it in 1971 expansion tank and all. After all of this my question is who is right???.

Kenneth -- check out this pic of an early '66 (VIN 00224) big block Red/red convertible that I photographed at Spring Knoxville 1991. There's a bunch of '65 regular BB production stuff mixed with expected changes for 1966 MY.

[Larry M.]

Re: Early 66 Big Block Expansion Tank and HP question

VIN #3279 was built on approximately October 18, 1965 according to the CORVETTE BIRTHDAY BOOK 5th Edition.

I would also re-check the TRIM TAG date, it is probably C06 and not 006. The C06 would mean an AOSmith Body Build date of October 6, 1965. This would correlate relatively well with a Car Build Date of October 18. There was typically a 7-14 day (transit) time lag between a body built at AOS in Michigan and the car build in St. Louis.

Based on this, I am not sure where your "early August" car build comes from?

What is stamped on the engine pad? Does the engine assembly date and the engine VIN Derivative correspond to the car VIN? Does your car have a rear sway bar and bolted u-joint retainers for the half-shafts?

A car with a 3000+ VIN is too late to be a prototype or pilot car.

Larry

[Joe L.]

Re: Early 66 Big Block Expansion Tank and HP question

Thanks for the clarification on the HP question.

The battery is on the passenger side as is the hood support. The expansion tank numbers are 3155416 and 65 M

VIN is 194376S103279

Trim Tag

Chevrolet
006

Style 66 437
Trim 418
Body A-O 622
Paint 980

Ken-----


The car was built about the mid-October time that Larry mentioned. The supply tank with a code of 65M was manufactured in December, 1965. It's very unlikely that this particular supply tank was originally installed on the car. The only way I could see that might have happened is if the car was held off-line for a while awaiting repair AND the repair included replacement of the supply tank.

Still, it's possible that the car was originally built with a supply tank and the supply tank was replaced very early-on in SERVICE.

What radiator is installed in the car and what is the date on it?

[Michael H.]

Re: Early 66 Big Block Expansion Tank and HP question

The battery is on the passenger side as is the hood support. The expansion tank numbers are 3155416 and 65 M

If the coolant supply tank is dated M (December) 65, wouldn't that indicate that it was installed at least some time during or after December 65, a few months after the car was built?