1972 Cadillac Engine size question....

the carb shop list it as the carter for the 365 in the years mentioned. but according to them Rochester built the same carb for GM also. the kit interchange. which is again a mystery. it's a 58 engine with a 58 number on it. a 390 with a carburetor off a 365. you got to love GM
 
Many of these type changes were made by GM for drivability issues, knowing how the vehicle was going to be used. Possibly the carburetor had smaller jets that would not load up the engine with fuel at the slower speeds that a funeral procession travels. I checked the Factory Parts Book, and all that it shows for the car is the Carter AFB. That doesn't preclude the commercial chassis having a different carburetor. Unfortunately, the book that I have is a 1967, so a lot of "history" is lost, since many parts might have been discontinued. I couldn't even find a rebuild parts kit for the Rochester carburetor number. The best that I could find elsewhere was a general reference to the type of carburetor it is, and the years of application.
 
Ed asked a question a while back in this thread and I don't think that anyone has answered it yet. I saw a lot of talk about carburetors, but no mention to leaded/unleaded.

Ed, you asked, "Was '73 leaded or unleaded?"

I can say for sure that my '73 Superior Cadillac used unleaded gas. I also have a '73 Ford LTD Squire that calls for leaded. I always thought it interesting that Cadillac was a couple of years ahead of Ford when it came to using unleaded.
 
Ed asked a question a while back in this thread and I don't think that anyone has answered it yet. I saw a lot of talk about carburetors, but no mention to leaded/unleaded.

Ed, you asked, "Was '73 leaded or unleaded?"

I can say for sure that my '73 Superior Cadillac used unleaded gas. I also have a '73 Ford LTD Squire that calls for leaded. I always thought it interesting that Cadillac was a couple of years ahead of Ford when it came to using unleaded.

thanks. the 73 S&S I had did not have a catalytic converter under it. it did have the smog pump same as this 68. but had been repainted so I don't know if it was labeled. it did not have the small filler neck. this is what I go by for unleaded only. now I know that the 70 we took the radiator support off did not have a smog pump on it. I have been told that only the Commercial chassis engines has the smog pump till the 73 model went to unleaded and the converter on the Fleetwood. just one more difference in the CC engines.
 
In the 73, on the instrument panel under the gas gauge it listed "unleaded fuel only". Don't remember exactly how it was written, but it was there.
 
more 390 info

If a 58 coach or car has a 390 it was changed after 1959. In 58 you would have had a 365 cubic inch engine. All 390s were not the same engine. The 59-62 models are the same engine. The 1963 390 is a different engine. We found this out when rebuilding a 61 390. One of the parts came in and did not fit. The old part fit inside of the new one. Back to the parts store. They insisted the part was for a 390. We showed them our old part. When they said they just ordered a 63 part as they were all the same we knew what our problem was. The 63 390 is a one year engine. The 331, 365 and 390 blocks are the same design. The block was used from introduction in 1949 through 1962. It was bored out as needed for more cubic inches. The 1963 engine is a one year engine. The hydramatic trans was used by GM for many years. The earlier ones had no Park (P) position. You had to put the car into reverse after shutting off the engine. These transmissions had 2 Drive positions. The first or left D was a 4 speed and the right side was a 3 speed. My owners manual says to use the right side (3 speed) for driving in snow, ice or muddy conditions. Pontiac also used this trans for many years.
M.
 
thanks. the 73 S&S I had did not have a catalytic converter under it. it did have the smog pump same as this 68. but had been repainted so I don't know if it was labeled. it did not have the small filler neck. this is what I go by for unleaded only. now I know that the 70 we took the radiator support off did not have a smog pump on it. I have been told that only the Commercial chassis engines has the smog pump till the 73 model went to unleaded and the converter on the Fleetwood. just one more difference in the CC engines.

My 1968 Cadillac shop manual starts off the chapter regarding the A.I.R. (air injection reactor) pump by saying, "The A.I.R. system is installed on ALL 1968 Cadillac cars". It also goes on to say, "The A.I.R. system requires a specially calibrated Quadrajet 4MV carburetor. The idle mixture screws have an extra long needle taper to provide finer mixture adjustment".
 
If a 58 coach or car has a 390 it was changed after 1959. In 58 you would have had a 365 cubic inch engine. All 390s were not the same engine. The 59-62 models are the same engine. The 1963 390 is a different engine. We found this out when rebuilding a 61 390. One of the parts came in and did not fit. The old part fit inside of the new one. Back to the parts store. They insisted the part was for a 390. We showed them our old part. When they said they just ordered a 63 part as they were all the same we knew what our problem was. The 63 390 is a one year engine. The 331, 365 and 390 blocks are the same design. The block was used from introduction in 1949 through 1962. It was bored out as needed for more cubic inches. The 1963 engine is a one year engine. The hydramatic trans was used by GM for many years. The earlier ones had no Park (P) position. You had to put the car into reverse after shutting off the engine. These transmissions had 2 Drive positions. The first or left D was a 4 speed and the right side was a 3 speed. My owners manual says to use the right side (3 speed) for driving in snow, ice or muddy conditions. Pontiac also used this trans for many years.
M.

how do we have a 390 with a 58 serial number? according to John not were the 365 would be. I could under stand 390 heads on the 365 block to explain the different valves. but the mechine shop ordered the valve off the serial number to got the right one. they are the one that told me it is a 390. wonder if it's a late 58?
 
so tell me is the 74 a unleaded fuel engine. I know that the 73 was not though it was in the standard caddy's. I'm guessing they did not go unleaded fuel till the 75 76 years.

now then the 58 we have here has the 390 not the 383. as does the 63. though they are different engines they are the same cubic inches.

My 72 Sedan deVille with the 472 was the first year that had in the owners manual a recommendation for the use of unleaded fuel. It also recommended high octane 92 min. fuel. I tweeked the carb and detuned it a little ad I was averaging 23 mpg with it until it was hit by a drunk driver and shoved through the garage door. :893USA-Smilie-thumb
 
Hey Kenn, I thanked your post for the unleaded comment and not for the drunk driver comment. Just thought that I would make it clear that I wasn't thanking the drunk driver or something like that! :smiley3: :smiley3: :smiley3:
 
the started rec emending the year before the cars went to mandatory. but did it have the small opening filler on the gas tank. when you could only put in the unleaded nozzle in was when they went to unleaded fuel. Robers 75 has the smaller opening. that had been cut out as most of them were. the 73 S&S I had had the larger opening on it. I thought it was strange as the cars by 73 were unleaded only. I looked through my pictures and I did not take one of the dash. I do remember that they had a lot of different california cars only out in those years
 
in furtherance of the discussion:

...and pre-1968, was the 427. I can't imagine this engine getting the job done. And as far as the 383 in the 58 mentioned above, is this a Caddy? I know the 383 was a gas guzzler for Mopar.
Thanks to all for bringing this issue up!
Kevin Lynch
Candidate for nothing, Venice, FL
 
got my sizes mixed up 365 was the engine I was thinking of not 383. I can vouch for the 427 or was it 429? in the 66 it was a snappy performer in the black one of Jim's.
 
My '67 is a 429, my understanding is '67 429s use individual rocker arm supports, while the '65 and '66s use a single rocker arm shaft for each head, although the '67s can be back dated. I agree with Ed - it does seem to have pretty good get up and go, in spite of the heft of the car it's hauling around - and mine isn't the freshest engine on the block.
 
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