Engine Identity - The 1947 - Present Chevrolet & GMC Truck Message Board Network

harnalien · 09-01-2006, 05:53 PM

Is there anyway to visually find out if an engine is a 350 or 305. I think it is a replacement block, and not GM. It does not have the engine stamp on the front under the alternator. I can't get to the back of the engine by the dizzy to see the stamp there, and i don't think taking the heads off is in my skillset. is there anywhere else i can look? for now it won't be that big a deal because i won't be doing much performance enhancements, but i think i need to know when i get a new carb. any help would be appreciated.

piecesparts · 09-01-2006, 11:10 PM

Did you look at the edge of the block (right in front of the head on the passenger side of the block. Most GM motors have a lip sticking out with a number stamped into the metal. Can oyu get under the truck and use a mirro an flashlight to see the top of the block at the rear. The numbers are forged into the block and chances are if it is a replacement motor, then it would have a "M" forged into it. That would hint to the fact that it was a replacement built South of the border--where most were assembled.

jimfulco · 09-06-2006, 10:22 PM

Some engines have the last few digits of the casting number cast into the block sides. Might look around for that. Head casting numbers are under the valve cover between 2 sets of valve springs. That won't guarantee anything unless you're sure it's an unmolested factory engine.

krazymonkeys24 · 09-13-2006, 02:26 PM

like piecesparts said, there is a casting number on the front passenger side of the block. That would actually be your best bet, because the number stamped there will have everything from casting date, to displacement, to factory where it was casted. A quick google search for casting numbers will give you the info to decode it. You will almost definitely have to pull the alternator to see it and in some cases, the water pump as well.

harnalien · 09-15-2006, 03:53 AM

i'll look some more, but I've just decided to get a new crate motor to put in. I have no clue as to when i will get it, but since this will be a daily driver to replace my 98 blazer, and i need something that will give me years of reliability. hopefully in february. i'm going to get an exhaust system soon, as it should bolt up to the new motor. i like the engine packages that jegs offers. i just have to find a shop to put it in for me. i have no skills in that dept. can anybody recommend a shop in the dallas/ft worth area??

09-01-2006, 05:53 PM	#1
harnalien TruckincrazY Join Date: May 2004 Location: Haslet, TX Posts: 493	Engine Identity Is there anyway to visually find out if an engine is a 350 or 305. I think it is a replacement block, and not GM. It does not have the engine stamp on the front under the alternator. I can't get to the back of the engine by the dizzy to see the stamp there, and i don't think taking the heads off is in my skillset. is there anywhere else i can look? for now it won't be that big a deal because i won't be doing much performance enhancements, but i think i need to know when i get a new carb. any help would be appreciated.

09-01-2006, 11:10 PM	#2
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: Engine Identity Did you look at the edge of the block (right in front of the head on the passenger side of the block. Most GM motors have a lip sticking out with a number stamped into the metal. Can oyu get under the truck and use a mirro an flashlight to see the top of the block at the rear. The numbers are forged into the block and chances are if it is a replacement motor, then it would have a "M" forged into it. That would hint to the fact that it was a replacement built South of the border--where most were assembled.

09-06-2006, 10:22 PM	#3
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	Re: Engine Identity Some engines have the last few digits of the casting number cast into the block sides. Might look around for that. Head casting numbers are under the valve cover between 2 sets of valve springs. That won't guarantee anything unless you're sure it's an unmolested factory engine.

09-13-2006, 02:26 PM	#4
krazymonkeys24 Registered User Join Date: Sep 2006 Location: Kannapolis, North Carolina Posts: 23	Re: Engine Identity like piecesparts said, there is a casting number on the front passenger side of the block. That would actually be your best bet, because the number stamped there will have everything from casting date, to displacement, to factory where it was casted. A quick google search for casting numbers will give you the info to decode it. You will almost definitely have to pull the alternator to see it and in some cases, the water pump as well.

09-15-2006, 03:53 AM	#5
harnalien TruckincrazY Join Date: May 2004 Location: Haslet, TX Posts: 493	Re: Engine Identity i'll look some more, but I've just decided to get a new crate motor to put in. I have no clue as to when i will get it, but since this will be a daily driver to replace my 98 blazer, and i need something that will give me years of reliability. hopefully in february. i'm going to get an exhaust system soon, as it should bolt up to the new motor. i like the engine packages that jegs offers. i just have to find a shop to put it in for me. i have no skills in that dept. can anybody recommend a shop in the dallas/ft worth area??



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