what would 7.4 pushrods do for my stock engine and can i use PRC Gold Double Springs on stock heads or what mods would i need to install them at what point with a cam do i need a double roller timing chain so i dont screw the engine

 

Stock LS1 pushrod length is already 7.4". You don't change your pushrod length unless needed (changes in gasket thickness, milling heads, valve stem length, deck height, base circle diameter, different lifters, etc change pushrod length).

Yes you can use Patriot or PRC dual springs on stock heads, these are beefy springs that are usually installed with big cams (like the MS3 for example).

A double roller isn't something that is usually required, but is installed for extra insurance. Most op for a new LS2 timing chain and call it a day, but there have been documented cases of breaking them. But I don't know if they were related to harmonics imbalance or not.