03 BLACKOUTSSS

iTrader: (3)

Not really, but I wanted to brag a bit. I recently took a set of stock LT1 643 castings, and did my own port job to them. I didn't know how I did, so I got them flowed, and I got 285cfm @ .600" intake and 200cfm @.600" exhaust. Stock numbers I've seen as high as 220 cfm and 130cfm. Ported stockers I have seen (with stock size valves) up to 265 and 195. Aftermarket castings and pure race prepped heads are getting over 300 cfm, but 285 isn't too bad.

I have a set of 317s in the garage that I am going to start working on now, to see what I can get from them.