When I rebuilt my 235 in my 59 GMC about 10 years ago I paid about $1000 just for parts.
The high school I had attended 10 years prior to that (20 years ago now) had an excellent trades department. The auto shop even had a line boring machine, and they was a complete machine shop as well. The shop teacher jumped at the chance to rebuild an inline 6 if I paid for the parts.
Much cheaper to rebuild a small block V8, BUT........