not to hijack but i have a similiar experience with installing a small roller with almost exact same specs. went from a mopar .620 cam with 1.6 rockers to a cam dynamics .660 same specs as op. changes were to new springs, 1.5 rockers, and pushrods for length. i installed it at 106 as called for on cam card as i didnt check p/v clearance at different installed c/l. i netted no change at all. car has been fastest with the old comp cam .650 cam installed at 101 c/l. that cam has 290@.050, go figure.