What are the mod's and parts I would have to change?
The 230 Block Casting number is 3788406.
I did a Casting Number search on the internet.
Why is it that some Blocks are listed as 230-250?
But this 3788406 is only listed as a 230 block?
And would 1970-1975 250 cid parts,Head fit on this 230 block?
I gess im wondering if a Block casting is only listed as 230 cid.
There must be a reason why it can't be made into a 250 cid?

The difference between a 230 and a 250 is the stroke. A 230 has a 3.25" stroke while a 250 has a 3.53" stroke. Both have a 3.875" bore.

I've never done it, but I'd figger that you'd need to use the 250's crank, pistons and rods to make the conversion. The head should bolt on just fine.

They question is "why?" The advertised HP difference is only 15, same for torque. If you want to step up in power, a 292 would be a better choice, imo. Yeah, there would be a little more work with the motor mounts, but you'd sure get a whole lot more torque outta the deal. I love my 292, btw.

I have a 1972 Inline 6 250 with good internal parts,but the block is crack just under exhaust/intake on the water jacket. Head is ok.
I can get a Inline 6 230 engine casting number 3788406.
And since the only casting listing I could find on the internet said its a 230 block.
Im not sure if I can make this Block 3788406 into a 250 cid engine.
So can ALL 230cid blocks be made into a 250cid?
And since a 230 has a shorter stroke would a 230 cid run at a higher RPM,than a 250 cid?