Engine ID
Thread Starter
Race Director
Joined: Sep 2002
Posts: 10,362
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From: San Diego - Deep Within The State of CONFUSION!
Engine ID
The 4-Bolt Main 350 that I just built and installed seems to be a curiosity. It is definitely a 4-bolt and definitely a 350. :yesnod:
Casting # at left rear of block is 3970010 and on the right side by the bellhousing it is stamped as an LT-5
The stamp pad in front of the right side cylinder head is blank because it's been milled. http://WWW.MORTEC.COM has info, but only to say that it is a 69-80 block. Anyone out there have anything more conclusive? Is that LT-5 stamping significant?
Casting # at left rear of block is 3970010 and on the right side by the bellhousing it is stamped as an LT-5
The stamp pad in front of the right side cylinder head is blank because it's been milled. http://WWW.MORTEC.COM has info, but only to say that it is a 69-80 block. Anyone out there have anything more conclusive? Is that LT-5 stamping significant?
Safety Car
Joined: Dec 1999
Posts: 3,602
Likes: 837
From: PA
Re: Engine ID
Paul,
The 3970010 casting is a VERY common block used in passenger cars and trucks during the 1969-1980 time frame. The fact that it has four bolt main bearing caps doesn't really help... Trucks tended to have them more than cars; plus the fact that they can be easily added to a block that originally had two bolt mains by a competant machine shop.
The casting date should be on the opposite side of the bellhousing mounting flange from the casting number... This would allow you to narrow things down a bit. At the very least, you should be able to identify a possible model year this particular engine was used.
It is possible to "raise" numbers on a pad that has been decked... The police use such a method to read serial numbers on firearms and stolen property that have been ground off. I have also heard that heat applied to pad with a torch can also be used to make them legible again although I have no experience with this. It all comes down to how important it is to you to identify this block.
The LT5 on the bellhousing is insignificant... Probably just some sort of mold identification. The casting number would be of more benefit to identifying the possible applications for this particular bellhousing.
Good luck with your research.
Regards,
The 3970010 casting is a VERY common block used in passenger cars and trucks during the 1969-1980 time frame. The fact that it has four bolt main bearing caps doesn't really help... Trucks tended to have them more than cars; plus the fact that they can be easily added to a block that originally had two bolt mains by a competant machine shop.
The casting date should be on the opposite side of the bellhousing mounting flange from the casting number... This would allow you to narrow things down a bit. At the very least, you should be able to identify a possible model year this particular engine was used.
It is possible to "raise" numbers on a pad that has been decked... The police use such a method to read serial numbers on firearms and stolen property that have been ground off. I have also heard that heat applied to pad with a torch can also be used to make them legible again although I have no experience with this. It all comes down to how important it is to you to identify this block.
The LT5 on the bellhousing is insignificant... Probably just some sort of mold identification. The casting number would be of more benefit to identifying the possible applications for this particular bellhousing.
Good luck with your research.
Regards,
Thread Starter
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Re: Engine ID (Rowdy Rat)
The casting date should be on the opposite side of the bellhousing mounting flange from the casting number... This would allow you to narrow things down a bit. At the very least, you should be able to identify a possible model year this particular engine was used.
That's where the LT-5 is located. Not much more that is decipherable.
That's where the LT-5 is located. Not much more that is decipherable.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Re: Engine ID (SanDiegoPaul)
Your right Paul the block is a '68 through '80 block used in every thing from corvettes to trucks. Even 302 Z28s where powered by it.
Now the bad news. The passenger side rear should have a "casting date code" not a stamped code. "L" for the twelfth alphabet letter is December. The "T" is mostlikely a 1 is for the first day of December. Finally the "5" would be for 1975 as the year ending in 5 during product run. Hope this helps.
By the way who built your 383? Local? SD?
Now the bad news. The passenger side rear should have a "casting date code" not a stamped code. "L" for the twelfth alphabet letter is December. The "T" is mostlikely a 1 is for the first day of December. Finally the "5" would be for 1975 as the year ending in 5 during product run. Hope this helps.
By the way who built your 383? Local? SD?
