Labor Day Putting down your wrenches or time for MORE wrenching? 
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| | | Forums66 Topics128,005 Posts1,055,254 Members48,418 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | ok guys need help, i have a 52 chevy 1ton truck 3800 series.my bely is squealing real bad. The crankshaft pully and altenator [i put altenator on instead of generator] is smaller then water pump pully. My friend thinks it is a 235 motor. all numbers says it is a 261 1954 motor. i really don't know but my question is where can i find a pully for 1954. and r the 235 and 261 same pully. here is a few pics of motor pullypullypully | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | motor numberhttps://photos.app.goo.gl/zYqYnHJS7QmghrDP7 | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | | | | | | Joined: Mar 2010 Posts: 10,270 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,270 | Where did the the crankshaft pulley come from? If it is original, it should be for a 5/8" belt. Are you certain that it is for a 5/8" belt? Your water pump looks to have a pulley for a 5/8" belt. If both of those pulleys are for a 5/8" belt, then you need to buy a 5/8' belt and change the pulley on the alternator to a 5/8" pulley. Now if the crankshaft pulley isn't for a 5/8" belt, then you may have to buy a '53 water pump which comes with the narrower pulley. I don't know where you will find just the pulley. Even if you do, it is a bear to get the old one off and the new one on. The water pump costs $129.95 at classicparts.com. Who knows, maybe yours is about to lose a seal some time soon anyway. Easy fix. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | the crankshift and aterenator r the same. the water pump is bigger. they were part of the truck when i bought it | | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | It looks like the balancer is for a 3/8" belt. So as Carl says, you just need a 1953-54 pump, which comes with a 3/8" belt pulley.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | Carl, can u tell me for sure whether its a 235 or 261 motor | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | jimbo 24, Please provide the codes that you find on the photos on this page. http://www.1954advance-design.com/Web%20images/casting-code-photos/codes-ser-nums.htmlIf you want to post photos of those codes, please also post what you think the codes are (as numbers/letters - some photos are hard for use to read/guess). The CON3 code you posted is not useful - it indicates that the head travelled on CONveyor #3 in the head factory. If the block casting code is 3733950, that code was used in 1955-1957 on 261 truck blocks (USA). The block and head date-casting codes will ID the year in which the block and head were cast. The code pressed into the block behind the distributor (Engine Serial Number) usually IDs the year and size of the truck in which the engine was installed. | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | sorry on the headhttps://photos.app.goo.gl/U5bJGK23SSRFMTJn6 | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Looks like all those codes are from a block?
950 = ??? (I have never seen a meaning/translation for that type of code : I have seen 850 and 950))
CON4 = CONveyor #4 in the casting plant
J 19 0 = block casting code J = 11 19 = 19th 0 = 1960 (if it is a 261, or a high-pressure 235) -> from an earlier post, it is most likely a 261 | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | First link are codes on the side of the head:
It is not in the location of a head date casting code, and not in the location of a head casting code. Those two codes are under the valve cover (as shown on a page that I linked-ton in an earlier post).
If I am incorrect, someone will post a correction. | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | 3836850 That is the head casting code: for all 261 USA truck engines. | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | ok thanks Tim. Now back to my first question, do i need a 3/8pully with water pump | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | I like all the pulley grooves to match: 3/8, or 1/2, or 5/8ths, or etc
However, some people have posted/recommended that you can use the smallest size for your combination? That might not work in a wide pulley - the narrow belt might "ride" on the bottom, not on the sides?
Wait to hear from others. | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | thanks guys, appreciate it | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | Carl, u said the crankshaft pulley should be 5/8 for 261 motor. correct/ then i will change my alternator and water pump pulley to match. what do u think? | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | What pulley size is on the harmonic balancer? What puller size is on the generator? It looks like the pulley size on your water pump is wide - 1/2" or maybe 5/8" The standard generator in 1954 used a 3/8" pulley (even on 261 motors - it looks like that in parts manual). The optional higher-rated generator in 1954 used the wider pulley, maybe 1/2" or 5/8" (as shown on your water pump). Do all of your pulleys seem to have the same size grooves? If yes, the wider pulley should be correct? http://chevy.oldcarmanualproject.com/parts/1929_54http://chevy.oldcarmanualproject.com/1929_57 | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | no they don't. the crankshaft pulle that is why i wanted to know correct size crank pulley for 261.y and alternator pulley r the same. water pump is bigger. that is why i get all the squealing. | | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | Unless you have the engine out I wouldn't worry about the crank pulley. I would just put a 1953-54 pump on it and be on your way.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Jul 2013 Posts: 363 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 363 | | | |
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