Small block I.D. help

[R N.]

Hello All,

Looking at a small block LT-1 (1970), however the block casting number is wrong. It's got the right heads, intake, carb, etc. but the block isn't right.

The casting # is 14016379 (LH rear of block)
On the RH rear of blockis cast GM and what looks like 5.7L and a cast date that I can only make as 85.

On the side of the block, under the exhaust manifolds (on both sides) is CFD and directly under that is 379. Both of these are large cast numbers about 1-1/2" high.

The stamp pad is very small (1" wide x 1-3/4" approx.) and no stampings.

Can someone help me out with the ID. Is it a 4-bolt block?

As usual, thank you for your help.

Kurt

[Joe L.]

Re: Small block I.D. help

Kurt-----

GM #14016379 is a 350 cid small block originally used for 1977-79 Chevrolets of all models except Corvette. It was also used for SERVICE applications, too. I believe that all variants of this block were manufactured with a 2 bolt main configuration. However, it is possible that some, especially SERVICE blocks, may have been manufactured with 4 bolt configuration. Block casting number generally has nothing to do with main bolt configuration. Just about any 350 block can be built up by the factory into either 2 or 4 bolt configuration. It's just that some block castings are GENERALLY manufactured in only 1 main bolt configuration. Remember, the casting number on the block is the part number for the block casting and is related ONLY to the casting. Main bolt configuration is a machining-related item. So, finished blocks with both main bolt configurations can have the same casting number (which appears on the block) but different finished PART numbers (which appear nowhere on the block).

I don't think that this block was used in PRODUCTION applications as late as 1985. However, it could well have still be in production for SERVICE applications at that time. It may, even, have started life as a GM "Target" engine. If so, look for a "Hecho En Mexico" cast on the left side bellhousing flange.

The "CFD" refers to "Central Foundry Division". That doesn't say much, though. All of the GM foundries, where all GM small blocks were cast, were part of Central Foundry Division. So, that information is moot.

The fact that the stamp pad has no stampings tells us that this is almost certainly a SERVICE block. It may have started life as a bare block, partial engine (short block), or a complete engine. By 1985, I don't think that nay of these had pad stampings for SERVICE engines.

The "379" is simply a derivative of the block casting number. In this case, it likely identified components of the patterns used to make the casting.

The small stamp pads are a characteristic of later small blocks.

[R N.]

Re: Small block I.D. help

Wow Joe! You amaze me with the wealth of knowledge you have. Thank you ever so much.

What do you and the other members feel about builting a LT-1 around this block?

Thanks again,

Kurt

[Joe L.]

Re: Small block I.D. help

Kurt----

From a FUNCTIONALITY perspective, I think that the basic block will be just fine, if incorrect, in terms of "numbers", "dates", etc. It is true that these later blocks are lighter and that means that some strength was taken out. However, they're PLENTY strong enough for any street LT-1. Now, we're just talking about the basic block. To reconfigure it to bring it up to LT-1 standards is going to require a lot of work. If it happens to be a 4 bolt configuration, then you've "dodged that bullet. Otherwise, to have full LT-1 configuration you'll need to add 4 bolt mains. That won't be cheap. Then, you'll need to acquire a steel crank, better rods, and better pistons.

When you get right down to the nitty gritty, it might not make a lot of sense to spend a lot of money on this block. It so happens that the 3970010 blocks are really pretty plentiful. You may or may not have to add 4 bolt mains to the block, but at least you'll have a correct block. And, you'll need the other items, too. But, once again, you'll be building it around a correct block. This will have value. Not from a functional perspective, of course, but from an originality perspective.

[R N.]

Re: Small block I.D. help

Thank you agian Joe.

Kurt