My Transformation 5.7 Gen 3 in 74 Dart Sport

That is why I used the PSI 1511 springs, they are good for up to .625 lift and have enough spring tension for most of the after market shelf cams made for the 5.7 and 6.4 VVT Hemis. I put a 6.4 cam in my 2012 Challenger R/T in 2014 with these valve springs and than in 2019 I put in a custom ground cam with .590 lift in it. Cam grinder spec the same valve springs. The Mopar Performance valve springs are rated about the same as the PSI springs and they are spec for the Comp 270 VVT cam (.615/.609 lift) through Mopar. The part# for the Mopar Performance spring kit is P5160074.