Please i need help

Tigstud

Member
I have what I thank is a Buick 350 but none of the numbers on the block match anythingthat I can find on here 20210414_223645.jpg
 
On the rear of the engine block up top to where the tranny bolts to you should see the # 55
The "2" 5's can be different in sizes.
I believe that is the 350 block.
If it's a # 455 then its a big block I also believe.
 
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1st. is the distributor in the front??? 2nd. how many bolts hold on the valve cover??? Five is a 400/430/455. Six is a small block Buick. What color is the engines original paint color??? Red is '74 or earlier. Blue is '75 or later.

Tom T.
 
1st. is the distributor in the front??? 2nd. how many bolts hold on the valve cover??? Five is a 400/430/455. Six is a small block Buick. What color is the engines original paint color??? Red is '74 or earlier. Blue is '75 or later.

Tom T.
6 bolt valve covers the engine appears to have originally been blue
 
1st. is the distributor in the front??? 2nd. how many bolts hold on the valve cover??? Five is a 400/430/455. Six is a small block Buick. What color is the engines original paint color??? Red is '74 or earlier. Blue is '75 or later.

Tom T.
On the rear of the engine block up top to where the tranny bolts to you should see the # 55
The "2" 5's can be different in sizes.
I believe that is the 350 block.
If it's a # 455 then its a big block I also believe.
20210415_143915.jpg
 
It's a little hard to make out the back numbers but I see one 5 and having the 6 valve cover bolts like Tom mentioned i'm pretty sure its a 350.
I don't know what the X is on the back casting? maby a replacement block? Let the the experts chime in..
Being that it's a blue color would mean its a low compression 1977 to 1981 motor but again not sure sure of the X on the back.
 
I'm pretty sure that its the casting # for a late 350.
Try the forum "V8Buick.com"
It seems to be a more active forum lately and is wealth of info..
 
Do you know what car it came out of?
Also this casting numbers info came from the 350 section on the engine links on this forum.
I think the #1 on your block was cast on the weak side and can't be seen?? Unless its a replacement block which might explain the X
Capture.PNG
 
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The numbers stamped on the front of the block follow a standard GM format The first character designates the GM division. The last 8 characters match the last 8 of the vehicle's VIN.

5 (unclear) = GMC division. This does not make sense. We have no records indicating GMC used Buick 350s. Stamping is not clear. If that is a 3 it makes sense where:

3 = Oldsmobile division.
6 = last digit of model year. This must be 1976 based on engine color and year range of when Buick 350s were built.
W = Willow Run, MI. This is the vehicle assembly plant.
128902 = vehicle's individual production sequence number

Attached is a 1976 GM VIN decoder card which shows meaning of each character.

The 430 numbers stamped on the block near the head are a build date code. There should be 2-letters in front of these digits to indicate indicate engine type and usage. We would expect some code between PA and PU if engine was installed in a Buick.

Most of the Buick 350s that year went into Buicks, but some were installed in Pontiac and Oldsmobile X-body cars. The letter codes on the block are probably different for non-Buick cars. The letters and numbers were stamped at different times based on what we have seen on many of these blocks. Sometimes the letters and numbers are stamped so far apart that part of the code is covered by the head gasket. If the heads are going to be removed, the letters may become visible.

Based on the 124 (1?) 748 block casting number and other details, I think there's no doubt it's a Buick 350. If more research is desired we can research other casting numbers on the block, heads, and manifolds. Beyond that, there's the part numbers on the distributor, carb, starter, alternator if the parts look original.
 

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