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I believe that the 4-speed manufacture casting and build codes and dates and VIN code derivative will tell the true story.
I personally believe that if the car was born with a Powerglide trans there will still be a few signs (extra holes, component dates etc) to confirm it. Depends on how deep you want to dig.
Removing the paint from the engine pad will also help.
Personally, I would probably agree with the Trim Tag until I followed and disproved every possible lead. That would take a few hours. But that is just me.
So, I finally got back down to the car to go over as many issues and numbers as possible, without disassembling the car and the picture below shows the numbers I collected.
My personal feeling, is that with the correct rear axle codes and dates (on a rear assy. that has never been out of the car); add to that the clutch cable opening on the firewall is unmolested, factory original; also, there are NO other signs of a suggested PG install, anywhere; console & interior firewall openings, etc.. appear original, etc... that the car is indeed an honest car.
There is a real curiosity with the tranny (of course, life is never that simple it seems) in that there is NO sign of anything ever being stamped on the pad where a VIN would normally reside. The cast surface appears unmolested. The build date is Mar. 3rd and the casting marks indicate a Dec., 1st week casting. Again, the dealer who sold him the car said it was all #'s matching (I know) and there's really nothing to suggest otherwise, with the exception of the VIN stamping.
I've also collected receipts for the work done to the car, since Roger bought it. He told me he paid to have real leather seat covers to replace the original vinyl and had the AC compressor changed to be able to run R134A.
Well, either that "AC" ECL is a factory mistake (An extremely rare possibility) or the car was originally equipped with a M35 powerglide AT and it was swapped out somewhere along the line for the Muncie.
The fact that while the casting dates are marginally close but the trans is not stamped makes me wonder if it was a conversion done shortly after delivery - perhaps by a dealer using an over the counter Muncie for a customer who wanted a 4 spd?
Absent some other original documentation - PoP, MSO, Bill of Sale - there is no way of knowing for sure.
But the rear axle codes are the standard equipment for an L79, M20, 3.36 posi...and the firewall looks vintage original.
Maybe a warranty replacement from the dealer, very early in it's life?
Could be, perhaps a combo of an ECL mistake and such a replacement? I am beyond my level of knowledge here, and am not sure there will ever be any way to know to an absolute certainty...........
So, I finally got back down to the car to go over as many issues and numbers as possible, without disassembling the car and the picture below shows the numbers I collected.
My personal feeling, is that with the correct rear axle codes and dates (on a rear assy. that has never been out of the car); add to that the clutch cable opening on the firewall is unmolested, factory original; also, there are NO other signs of a suggested PG install, anywhere; console & interior firewall openings, etc.. appear original, etc... that the car is indeed an honest car.
There is a real curiosity with the tranny (of course, life is never that simple it seems) in that there is NO sign of anything ever being stamped on the pad where a VIN would normally reside. The cast surface appears unmolested. The build date is Mar. 3rd and the casting marks indicate a Dec., 1st week casting. Again, the dealer who sold him the car said it was all #'s matching (I know) and there's really nothing to suggest otherwise, with the exception of the VIN stamping.
I've also collected receipts for the work done to the car, since Roger bought it. He told me he paid to have real leather seat covers to replace the original vinyl and had the AC compressor changed to be able to run R134A.
No sign of any stampings, ever.
You should correct that AM rear axle to be 3.36, not 3.66.
So, I finally got back down to the car to go over as many issues and numbers as possible, without disassembling the car and the picture below shows the numbers I collected.
My personal feeling, is that with the correct rear axle codes and dates (on a rear assy. that has never been out of the car); add to that the clutch cable opening on the firewall is unmolested, factory original; also, there are NO other signs of a suggested PG install, anywhere; console & interior firewall openings, etc.. appear original, etc... that the car is indeed an honest car.
There is a real curiosity with the tranny (of course, life is never that simple it seems) in that there is NO sign of anything ever being stamped on the pad where a VIN would normally reside. The cast surface appears unmolested. The build date is Mar. 3rd and the casting marks indicate a Dec., 1st week casting. Again, the dealer who sold him the car said it was all #'s matching (I know) and there's really nothing to suggest otherwise, with the exception of the VIN stamping.
I've also collected receipts for the work done to the car, since Roger bought it. He told me he paid to have real leather seat covers to replace the original vinyl and had the AC compressor changed to be able to run R134A.
No sign of any stampings, ever.
A few things to help or hinder:
The trans case #3853125 was only made for 1964-65 time period. After that it changed to #3885010. Based on this and no VIN derivative, the trans was purchased later and added to the car. It could have been to replace another Muncie or an auto.
The carb # 3230 is not a known Corvette carb. The date of 504 indicates 1965, October, 4th week (of October).
Carb and trans could be from a 1965 donor car......or just could be replacements.
I dunno. Hopefully you will eventually get to the truth.
The 418AC Trim ECL says the car was originally built with Powerglide, without power windows, headrests, shoulder belts, or 36-gal. tank. The engine now in the car is from a '67 Corvette, and the transmission and bellhousing are incorrect and were sourced elsewhere when the engine was swapped. The car would take a 350-point hit right off the bat for the block casting number and date.
The 418AC Trim ECL says the car was originally built with Powerglide, without power windows, headrests, shoulder belts, or 36-gal. tank. The engine now in the car is from a '67 Corvette, and the transmission and bellhousing are incorrect and were sourced elsewhere when the engine was swapped. The car would take a 350-point hit right off the bat for the block casting number and date.
You guys amaze me! Can't believe the knowledge. So glad I joined this forum
The 418AC Trim ECL says the car was originally built with Powerglide, without power windows, headrests, shoulder belts, or 36-gal. tank. The engine now in the car is from a '67 Corvette, and the transmission and bellhousing are incorrect and were sourced elsewhere when the engine was swapped. The car would take a 350-point hit right off the bat for the block casting number and date.
Now I'm really confused.
The #3892657 block casting number is shown as a late '66 (this is a July car) 327/350hp block on these websites:
The 418AC Trim ECL says the car was originally built with Powerglide, without power windows, headrests, shoulder belts, or 36-gal. tank. The engine now in the car is from a '67 Corvette, and the transmission and bellhousing are incorrect and were sourced elsewhere when the engine was swapped. The car would take a 350-point hit right off the bat for the block casting number and date.
Doug and John:
This car was built in the last week of 1966 model production, and is only 328 cars from the end of production. The NCRS Pocket Spec Guide indicates that the #657 engine block could have been used very late in production. However, this point is not specifically mentioned in the latest 1966 Judging Manual, although the JM does indicate that another casting besides #174 is possible. However, the current engine pad stamping is suspect in my opinion.....especially the "P" in "HP". I was thinking that if the car was originally a 327/300 HP Powerglide car, the "HO/HR" on the engine pad could have been redone to the current "HP" and the engine modified to 350 HP configuration.
The trans is from a 1964-65 model so we know it is not correct/original to the car.
But perhaps the engine is the original, just modified and restamped. FWIW.
Larry
Last edited by Powershift; 06-02-2016 at 09:44 PM.
While I see the different depth of the "P" versus the "H" next to it, I've seen varying depth stamps on many, many engines (Camaros mostly), so it doesn't immediately cause me to discount it. Especially considering the car has the right rear axle codes and dates and all other engine numbers (if original) appear correct.
Obviously, the tranny isn't the one it was born with. One could conjecture that it was an off the shelf replacement at a dealer, early in it's life, due to the lack of a VIN stamp.
What would you suggest as a paint remover to remove the engine paint to expose the raw casting underneath? I don't want to use a mechanical means of taking it off to prevent changing the look of the pad area. Aircraft paint stripper?
When I zoom in to the pictures of the stamp, I don't see any remnants of an underlying "E" or any other letter, so I'll need to strip the paint. I'll be looking for ghosting of filled in letters I guess.
While I see the different depth of the "P" versus the "H" next to it, I've seen varying depth stamps on many, many engines (Camaros mostly), so it doesn't immediately cause me to discount it. Especially considering the car has the right rear axle codes and dates and all other engine numbers (if original) appear correct.
Obviously, the tranny isn't the one it was born with. One could conjecture that it was an off the shelf replacement at a dealer, early in it's life, due to the lack of a VIN stamp.
What would you suggest as a paint remover to remove the engine paint to expose the raw casting underneath? I don't want to use a mechanical means of taking it off to prevent changing the look of the pad area. Aircraft paint stripper?
When I zoom in to the pictures of the stamp, I don't see any remnants of an underlying "E" or any other letter, so I'll need to strip the paint. I'll be looking for ghosting of filled in letters I guess.
Thanks for all of your help.
Most of us just use lacquer thinner and a soft rag..........and a little time. Paint stripper would also work I guess..........apply just a bit with a q-tip and then wipe off with a wet rag.
You need to get the engine casting date on the right rear of the engine. That may shed some light. Also pull the valve covers and get the cylinder head casting numbers and dates.
The bell housing part number is also not correct for this car. I can perhaps explain away the transmission being 64-65 due to a failure of an original, but having the wrong bell housing also is damning. They don't go bad unless you blow them up.......and I don't see that happening on this car.
A Powerglide car would of had a trans cooler bolted up to the front. You can check for threaded bolt holes in this location.
Don't know any more to tell you at this point. I guess you or the owner could try and have the engine pad and VIN derivative validated by Al Grenning. That would tie the engine to the car. Al might also have info on the late 1966 327 engines and their casting numbers........since he has an extensive library of engine pads to compare.
Larry
PS: Don't forget what I said earlier about the carb model number and date. The model number is not correct for a 1966 Corvette and the date you say in the spec sheet is not what is stamped on the carb. #504 is the fourth week of October 1965.
There are just a lot of things that are not coming together to support an original 1966 327/350 HP 4-speed with air conditioning.
Last edited by Powershift; 06-02-2016 at 10:44 PM.
05-25-2016, 12:37 PM
