And what if the used engine you end up with is in just as bad of shape? That's a very likely scenario with an unknown ISX. Then you will be even further in the hole in every way possible. You need to beg borrow or steal the money to have your current engine inframed PROPERLY, no shortcuts. That's the only way your going to get out of this mess.
And unless that crank is heavily and deeply scarred .. a few scratches would not stop me from polishing it up and just re-using it.
The used engine I was referring to is from a friends truck that was hit in the rear and totaled. 300k on the clock. It’s a 450st Cpl 2732. Current engine is cpl2733. I would still be tearing down current engine and overhauling to Rawze specs when the funds allow.