My 88 Olds wagone U/SA 10 Pennies

[Jeff Stout]

Originally Posted by SSDiv6

Normal for the the Oldsmobile 307 and 403 blocks.
They are of a lightweight design, light and have scalloped and windowed mains. For a full race engine, you can fill the block and used a girdle, or sleeve to a 307 bore size, a 1968 thru 1971 high nickel block.

Yes block was filled to bottom of water pump holes. Didn't know we could run a stud girdle. Ill look into that. Block was decked. We actually had to cut .034 to get zero deck. I have a 71 350 block but being a budget build I didn't want the expense of sleeving down to 307 bore