Emissions SB heads

I guess I should give more particulars. Don't need to drill all the way thru, 1/4" is more than enough and use never seize on the tap to catch shavings. I used 1/8" long set screws so you only need 2 good threads for them. For added security I center punched close to the edge of the hole after I put the set screws in to keep them from backing out. And I don't blame you thats just too cold. BRRRRRRRR!