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rico_bob · 04-02-2005, 12:09 PM

Need some help with this 347 motor.
Can someone tell me what all these numbers mean?
B 34707228
How do I know if it came out of a car or truck?
Thank you.

The 55-59 GMC Truck actually came with the option of two V-8 engines: The 336 V-8 and the 347 V-8.

From the 55-59 GMC Maintenance Manual:

Quote: "The serial number on 8-cylinder engine is stamped on block on right side below manifold to front of drain cock...."

From section 8 page 439: There is a table here of bore sizes............ The manual calls them "Cylinder Bore Selective Sizes" Under a table titled "Code Stamped on top of Block"

Code B = bore size 3.9380 to 3.9385

The standard bore size range was from 3.9375 to 3.9400.

My best guess is that the B in front of the number is the bore size code of 3.9380-3.9385 and (my experience is) that the rest of the numbers refer to the date of the engine build 07(July) 22 [day] and 8 (year 1958).

That is my 2 cents worth. Visit my web site often. rico_bob

04-02-2005, 12:09 PM	#2
rico_bob "Treasure the Ride" Join Date: Nov 2001 Location: Mid Michigan, Harrison Michigan, USA Posts: 682	GMC Maintenance manual says.. Need some help with this 347 motor. Can someone tell me what all these numbers mean? B 34707228 How do I know if it came out of a car or truck? Thank you. The 55-59 GMC Truck actually came with the option of two V-8 engines: The 336 V-8 and the 347 V-8. From the 55-59 GMC Maintenance Manual: Quote: "The serial number on 8-cylinder engine is stamped on block on right side below manifold to front of drain cock...." From section 8 page 439: There is a table here of bore sizes............ The manual calls them "Cylinder Bore Selective Sizes" Under a table titled "Code Stamped on top of Block" Code B = bore size 3.9380 to 3.9385 The standard bore size range was from 3.9375 to 3.9400. My best guess is that the B in front of the number is the bore size code of 3.9380-3.9385 and (my experience is) that the rest of the numbers refer to the date of the engine build 07(July) 22 [day] and 8 (year 1958). That is my 2 cents worth. Visit my web site often. rico_bob __________________ If you think you can you're right. If you think you can't you're still right. Trucks: '56 SWB; '57 SWB; '63 C-10 Current projects: 1963 Long Fleetside for the wife! '56 for the daughter. Visit us at: www.ricos-rods-and-relics.com Last edited by rico_bob; 04-02-2005 at 12:14 PM.