IQ52
Well-Known Member
It is unlikely any valve float is being caused by the 440 Source valve springs. The 924 springs that Comp recommends for that camshaft have less seat and open pressures than the 440 Source springs. There may have been an error in installed heights when switching to other retainers, or another guess would be incorrect lifter preload. There are two different lifters from Comp Cams for that camshaft and the lifter preload requirements are very different. Set up correctly the 440 Source valve springs will handle that cam throughout it's 2000-5800 rpm range.
350-360 rwhp if very stout for a 383.
350-360 rwhp if very stout for a 383.