350 block differences - The 1947 - Present Chevrolet & GMC Truck Message Board Network

zac · 02-10-2011, 03:45 PM

I was checking the engine stamping codes on the pad on the right-front of all the 350 blocks I have, just checking to see where they came from. There are six 3970010 blocks, the last one I bought last fall off Craigslist, it's the newest with an Aug '78 cast date. The pad at the front of the engine on this one is about half the size of the other ones (see pictures). Is this just some pointless variation, or is there something else to it? It has no numbers on the pad, which makes me think the block may have been decked.

**Captainfab** · 02-10-2011, 05:02 PM

That's just the way the blocks are from about '78 on up. I guess GM was just saving a little bit of cast iron bu eliminating some of that pad that wasn't necessary

zac · 02-10-2011, 06:32 PM

You know me and my son were talking about that, it seemed logical but kind of ridiculous at the same time. Change the casting just to save a little bit of cast iron? I believe it.

68gmsee · 02-10-2011, 08:56 PM

Yeah, when you make thousands of castings a few ounces or maybe even a 1lb shaved of the engine block would save thousands. But, don't forget that it also reduced the overall weight of a vehicle.

Government mandated mpg requirements made these companies do some weird things. I remember reading that to cut overall weight to increase gas mileage they asked the engineers to come up with any method they could to decrease weight without diminishing integrity. Thinner metals and use of plastics was a definite outcome of this.

rfmaster · 02-11-2011, 11:10 PM

Quote:

Originally Posted by 68gmsee

Yeah, when you make thousands of castings a few ounces or maybe even a 1lb shaved of the engine block would save thousands. But, don't forget that it also reduced the overall weight of a vehicle.

Government mandated mpg requirements made these companies do some weird things. I remember reading that to cut overall weight to increase gas mileage they asked the engineers to come up with any method they could to decrease weight without diminishing integrity. Thinner metals and use of plastics was a definite outcome of this.

Yep -

Over the years it got so bad that later on GM forced Melling to re-design their 'tried and true' oil pump housing to reduce weight! The few ounces of cast iron that they were able to take out resulted in cracked oil pump housing and people like us being screwed in the process.

http://www.chevelles.com/forums/showthread.php?t=336701
http://www.chevelles.com/forums/showthread.php?t=153113

//RF

02-10-2011, 03:45 PM	#1
zac Registered User Join Date: Jul 2008 Location: louisville, ky Posts: 502	350 block differences I was checking the engine stamping codes on the pad on the right-front of all the 350 blocks I have, just checking to see where they came from. There are six 3970010 blocks, the last one I bought last fall off Craigslist, it's the newest with an Aug '78 cast date. The pad at the front of the engine on this one is about half the size of the other ones (see pictures). Is this just some pointless variation, or is there something else to it? It has no numbers on the pad, which makes me think the block may have been decked. Attached Images

02-10-2011, 05:02 PM	#2
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,246	Re: 350 block differences That's just the way the blocks are from about '78 on up. I guess GM was just saving a little bit of cast iron bu eliminating some of that pad that wasn't necessary __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

02-10-2011, 06:32 PM	#3
zac Registered User Join Date: Jul 2008 Location: louisville, ky Posts: 502	Re: 350 block differences You know me and my son were talking about that, it seemed logical but kind of ridiculous at the same time. Change the casting just to save a little bit of cast iron? I believe it.

02-10-2011, 08:56 PM	#4
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: 350 block differences Yeah, when you make thousands of castings a few ounces or maybe even a 1lb shaved of the engine block would save thousands. But, don't forget that it also reduced the overall weight of a vehicle. Government mandated mpg requirements made these companies do some weird things. I remember reading that to cut overall weight to increase gas mileage they asked the engineers to come up with any method they could to decrease weight without diminishing integrity. Thinner metals and use of plastics was a definite outcome of this.



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