If you milled your head .060" to .125" I can give you a part number on new fresh bolts that will work that you can pick up at your local Chevrolet house. I used them on my 261 with a .060" milled head and decked block. They worked great and I felt much better using fresh bolts that weren't stretched no telling how far. They are head bolts from the old 5.7 liter Chevrolet-Oldsmobile diesel. The short bolts are Group 0.293, part number 22510580. They are 3" long, the 235-261 bolts are 3 1/8" long, but if you have milled your head, they will work fine. The long bolts are Group 0.293, part number 22510579. They are 4" long, the 235-261 bolts are 4 1/4" long, but, again, if you have milled your head, they will work fine. The heads on these bolts are 13/16" heads, not 3/4" heads, but clear without any problems. If you want to mount an accessory on your engine, Group 0.293, part number 22520637 is a short (3" long) bolt with a 1" x 3/8" stud on the top of the head. Two of these bolts can be used at the left front corner of the engine head (above the generator spot) for an accessory mount alternator or A/C compressor. Being used on the 5.7 liter diesel, these bolts will torque up to 125 lbs. If you can't find them at the Chevrolet house, the Olsmobile also used the the 5.7 liter diesel engine. I have successfully used these bolts and have been satisfied with them!
