Re: 351 Cleveland sluggish and breaks up at 5000 rpm
As far as the valve springs, all you need to do is measure lift, preferably on the rocker side and easier that way, but be sure you have lash set to where you want it and you are careful. Once you have open and closed spring heights, many of us can get can get you pretty close, although I don't really fancy myself a solid roller guy, I'd probably lean on a buddy.
70 Sportsroof, 427 FE/489 cid, TKO-600, 31 spline 4.10, A/C. modified Mass-flo EFI/reprogrammed A9L/CnC ported Victor.