1965 Block 3858180

[Dave P.]

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[Joe L.]

Re: 1965 Block 3858180

I'm curious about a block of the above description that a guy on another car forum I spend time on has.

The stamp on the deck is T0924HC and the casting number is 3858180.

There are (2) 1-1/2" pipe plugs in the front of the block, behind the timing gear, into the water jacket. Neither of us have seen this on a small block before.

I was guessing that this is a Tonawanda-only thing, and that neither of us had seen it, because Tonawanda small blocks are fairly unusual.

How close am I?
Thanks.

Dave-----


Tonawanda small blocks are not unusual, at all. However, they are most unusual in Corvettes. The 3858180 block casting was, I believe, a Tonawanda-only casting; I don't think it was produced at Saginaw. Apparently, some of the Tonawanda-cast 3858180 blocks were shipped to Flint for machining /assembly and some may have found their way into Corvettes. Be that as it may, the engine in question was not one of those originally installed in a Corvette. The "HC" suffix code identifies it as a 1965 250 hp 327 installed in a full size passenger car with Powerglide. In addition, the "T" prefix code indicates that this engine was actually machined/assembled at Tonawanda. I don't think that any of the 3858180 blocks used in Corvettes, if any at all were utilized, carried a Tonawanda prefix code.

Once-upon-a-time there were LOTS of Tonawanda-cast and machined/assembled small blocks out there. These were found in most other Chevrolet car lines other than Corvette. After the "oil shock" of the early 70's, V-8 engines became less popular, Tonawanda ceased producing small blocks and most small block manufacture was consolidated at Flint.

A vestige of small block V-8 production did continue at Tonawanda for quite awhile, though. That was in the form of the 4.3L V-6. This small block V-8-derived engine was produced for many years at Tonawanda after small V-8 production ceased.

Big blocks have always been produced at Tonawanda, of course. They continue to be produced there to this very day, although production is very limited now. From 1965 to 1984 big blocks and components thereof were both cast at Tonawanda as well as machined/assembled at the co-located engine plant. Since 1984, all big block cast iron components have been cast at Defiance, OH and machined-assembled at Tonawanda.