A new block is about $350.00 + shipping from Jegs. I had my block dipped, flushed, bored .030, freeze plugs installed, and the crank turned turned and polished .010, for $300.00
When you say .030 it is really a raw figure. You cant buy a .030 piston, and expect it to fit in a .030 hole. It would never go in. You have to actually measure each piston, and bore the corresponding cylinders to each piston. Each rod is stamped with a number from the factory. After the machinst places the piston on the rod he should bore that particular cylinder to work with the piston he hung on the rod. Hanging pistons is for the machinst also. They usually heat the pistons up in an oven to expand the metal and then they slam the wrist pins through the pistons and rods FAST because they only have a very limited amount of time. After they cool, they get gauged indivually and each cylinder is then bored to match. Each manufacturer has a tolerance on what they say you should bore to when using their brand of pistons. It is never just one number, always a span from .0?? to .0?? so it is really up to the machinst. It is MUCH better to keep your own block. You take a "seasoned" 302 block that you know is good and any machinst will tell you to keep it. The ones you by from the factory and RAW and they have no way for the engine builder to really get the tolerances correct on placing new pistons in it. Some guys automatically will bore the new ones .030 anyway so they know that the tolerances are perfect for the pistons they are using.
Avg.
$100.00-125.00 for the boring. $50.00 for the dipping, flushing,cleaning. $20-25 for the freeze plug insertion. Much cheaper than a new block.
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