Originally Posted by sixpackgut
HotRodDave, that spring info you gave is wrong. The 6.4 installed height is taller than the 5.7. A 6.4 spring CB is around 1.4. When installed at a 1.98 in an Eagle head you would be right on CB with a 6.4 cam.

Another thing, the 5.7s springs CB measurements are all over the place. From 1.30 to 1.37. However, the stock mopar springs have really stout pressures.



Stock as deviled OEM heads , installed heights ....... Apache Intake 2.055 Exhaust 2.020
Eagle Intake 1.990 Exhaust 2.000..................When we did my 09 ram we removed the factory 0.081 spacer on a Eagle 5.7 and used a .030 shim to make give me some breathing room



Part # P5160074 is the Mopar performance spring for the Eagle heads that has a max lift of .625 designed to work with stock 5.7 keepers and locks, they are $280ish from Summit and 240ish from https://www.moparpartsgiant.com/parts/mopar-accessories_spring_valve-p5160074.html

1963 Thunderbolt 496FE 10.80 (still a work in progress)
1968 Mustang slow a$$ 428 FE
1971 Boss 351 Mustang 11.20@115mph
1993 Lightning 10.61 @ 129mph 408Ci A3 headed NA
1996 Viper GTS
2001 Lightning 8.99 @ 155MPH 5.4 Mod Motor
2009 Ram 9.65@144MPH 463CI G3 NA
2010 Challenger 9.91 @ 139MPH 408CI G3ci NA
2019 F150 (local dealer's Lightning package) ..11.90s