Originally Posted by cmb8065
I'm rebuilding a 400 ci sb. The heads were cracked and I have a good rebuilt set of 350 heads. They don't have the small steam holes like the 400s. Is there any way I can modify them to fit the 400 block? I have a friend who owns a machine shop and can do about any kind of machine work. Any info will be greatly appreciated. Thank you.
I'm currently running a 406 sbc, my cylinder heads were too thick to drill out the steam holes and I didn't find not having them to hurt anything...I talked to some local guys who have a lot of experience with 400s and they have never had any overheating issues or any issues not using the steam holes...If you can have them drilled for cheap, personally I would do it just bc GM did.