SW oklahoma rebuildable 70-74 318

I am now looking for a rebuildable early 70 318 Motor, short block OR bare block.
During assembly of my cuurent motor which is 30 over, i have noticed one cylinder is rusted beyond repair. I am now forced to replace this block to complete my engine.
On a LOW budget, so the cheaper the better.
Thank you all.
preferably with in 60 miles of lawton, oklahoma.