BTR: LT1 .660" or .685" Double Spring Kit [Corvette, Camaro, Truck, LT1, L83, L86] calvo With an expanded line of

With an expanded line of part numbers

Custom ATS-V specific hand-crafted mufflers Designed to flow 35% over stock when valves are closed

We picked up our C7 ZR1 over 4 hours away and made it all the way home with one of these and the front end was still perfect

Valve Springs Included:Yes

Inherent is a rise and fall in pressure which takes time to achieve

BTR: LT1 .660" or .685" Double Spring Kit [Corvette, Camaro, Truck, LT1, L83, L86] calvo With an expanded line ofOption 1: . 660" Lift Dual Spring Kit for Gen V engines using stock rocker arms. Includes dual polished springs, matching Gen V specific titanium retainers, your choice of locators for stock or bronze guides, locks and seals. Spring specs are 155 lbs @ 1. 780", 380 lbs @ 1. 180", 400 lbs @ 1. 130, coild bind @ 1. 070" Option 2: . 685" Lift Dual Spring Kit for LS engines using Limited stock rocker arm setups and Roller Rockers. Includes dual springs,