The Stovebolt Site Forums The Shop Area Engine Shop 250 swap facts, ideas and opinions...

Didn't really plan for this to be my first post but such is life I suppose!
Ok I'm trying to identify a motor that was given to me that is a potential for a swap into my 46 1 1/2 (?) ton.
I already have a beautiful running 1976 1/2 ton van 250 (with integrated exhaust) mated to a th400 that I intended to swap into my 46. A previous owner swapped in a gmc 228 which is beyond seized so I'm figuring the 250 should fit.
Now the wrench...
I was given what I believe to be a different year 250 and would likely opt for the less smog equipped, more hp motor of the two if I can make that determination. The "mystery motor "has no smog equipment, (I'm in CA) I was told it was a 66. I don't believe that now and am looking for ideas what this motor came from and which is better for a daily driver truck.
Block: con2
377127 d127 right above dip stick
Intake casting:3859381
Exhaust casting 3881825
Looking at my note, I don't have the stamping by the distributor so I'll add that tomorrow. Oh! And this motor also has a broken (3 pieces) exhaust manifold so if I decide to run this one I need to source and purchase that.

Thanks!

230 and 250 inch engines are pretty much the same no matter what year they are. The main difference over the years was the head change to integrated exhaust manifold. All other heads are the same and swap freely. The 292 is the same basic engine with more stroke, they used the same heads as the smaller engines. If you have a good running engine, use it. The integrated heads work good when the exhaust isn't cracked, and in a light duty truck or van, it's likely OK. You won't gain HP or Power going to an older engine since the heads have the same design internally. The only advantage of older heads was the removable exhaust. If you are looking for an exhaust manifold, e-bay has new ones for John Deere tractors which used the 292 engine, same manifold trucks used.

As far as casting numbers go, the 230 and 250 can have the same numbers, you need to look at the piston tops to know for sure which engine it is. 250 used dished pistons, 230 had flat tops. Heads are all the same.

307 V8 pistons are a drop-in swap into the 250, and they raise the compression a little if you get the true flat-top pistons for the 307. Some later model aftermarket pistons have a chamfer around the edge of the piston that doesn't give as much compression boost as the originals. Speed-Pro makes a hypereutectic cast 307 piston that I've used on several 250 rebuilds along with a little hotter camshaft, and the combination of the compression bump and the cam really wakes the engine up in the low to midrange area. It takes some serious cylinder head, intake and exhaust work to get much of a high speed gain.
Jerry

Your 228 and 250 are about the same length, so the 250 should fit in where the 228 was.

Ed

Main problem with the swap will be motor mounts and radiator location. The 250 water pump will be quite a bit lower on the engine, this creates a problem with fan blades and lower radiator hose. Lowering the radiator isn't that hard, or you can use a late model electric fan, just don't tell anyone here you did!

Joe

F0415ccd is what's stamped by the distributor. I'm going to try the Google machine to see what that means.
My other 46 (2ton) I got as a project from a guy that got in over his head, mounted the motor and left everything else incomplete. That's got a 235 and the water pump is VERY low on the radiator, with no fan installed because it would hit the lower radiator hose. I think I've got that one sorted out (relocation bracket for the water pump) but wil need to take some measurements to see where the 250 water pump will land.
I am definitely trying to avoid an electric fan!
All this while building a house for my family so my progress is way slower than I want!