I want to rebuild the top of the motor and trying to find parts for it but can't find vin off the block. All I have found is 638 on the side of the blocks and 5.7 LG SGI F080. What years would I match this up to was told it was a crate motor. I have it in a 49 ford cab. 69 c-10 frame th350 transmission. 12 bolt rear end.

 

638 was the predominant 350 block from maybe 87 to 93 or so. 880 appeared then, and after a few years most blocks were that # instead. They're not much different.

In vehicles, the vast majority of them were in TBI motors (L05); trucks and B-bodies. In crate motors they were also in the ZZ series and some of the "replacement" products.

So, you have a 350.

Not sure about "find parts". Fill us in on the details here.

Which 12-bolt is it? Truck or car? They're VERY different.

 

I will have to look for details to find out rear end if it's car or truck the engine block has 5.7 LG SGI F080 Next to it. I was thinking June of 1990 crate motor but I'm not positive l. I'm getting oilnl out of position 5 spark plug so I was looking into oil seals and o rings. Oil pressure is idle around 60 until its warm then hangs high 50 to 70 then driving stays 60 then when I stop it drops to 20. Think the sending unit is bad. Just looking into getting new but want to make sure I get the right thing. Thanks again

 

None of that tells anything about that sort of thing. 5.7 tells that it's a 350, which the 638 casting number also tells you; pretty much all blocks have "LG" and "SGI" on them; F080 is the block casting date, in the format of the 08th day of the Fth month (the 6th, June) of a year ending in 0. The short block was probably assembled around 2 to 6 months after that, and then sold sometime later still.

The OPSU will probably depend more on what gauge is in it, than what motor. A stock SU won't work right with an aftermarket gauge for example. The port for it has been the same since the 50s if it's using the one behind the distributor, so if it's the stock gauge, then a SU for anything from the 50s to about 2000 will work. You could look up the one for a 69 C10 and it would be fine for a stock gauge, for that matter. But a reading of 50-60 psi driving then 20 idling sounds pretty normal to me, doesn't sound like there's anything wrong with it.

As far as oil in a cylinder, that's probably either the intake gasket, or the valve guide seals. Hard to tell what heads are on it; looks like they're perimeter-bolt valve covers, which means they're probably older than the block. Which then means it wasn't bought as a "crate motor", but rather, as a short block (whether new or rebuilt, could be either), and then some heads from somewhere. So who knows what condition they're really in. If you get the casting numbers from under the valve covers we can tell you what kind they are, anyway, if not anything else about them.

The rear doesn't really matter; I was just curious. Looking at it, it's almost certainly a truck one, being a 6-lug, which also means it's not from a 10 series (½ ton) truck, it's from a 20 or higher (¾ ton or more). Which is kinda odd since the front wheels are 5-lug which IS from a 10 series. But who knows what sort of mix & match somebody might have done to it.

Nice coolant recovery bottle.

 

Found rear end number.

 

Thanks on the compliment about the truck.