Join Date: Apr 2001
Location: Near Fairfield, CT
Never done what you ask, but I believe that 650 cfm is too much for a 258, especially because the heads have such poor flow.
There is some formula for displacement vs. cfm for optimal performace, but I don't remember what it is.
'82 Scrambler - NV4500/4.5" lift/33" Toyo MTs/4.0/twin stick, and my windshield washers work! Full 1/2 cab Cage
2004 Grand Limited 4.7 HO - OH Boy!
2010 Grand Laredo 5.7 Hemi - SICK - back for a second time!
"Both my Doberman and my Jeep can accurately be described as 'black and rust.'"