Is the stock pushrod length 6.400 in? And any idea what size I need with my stud mount roller rockers? Thanks

 

stock is 6.250.....there is no such thing as guessing, you need to mark the valve tips and run the pattern starting with stock length using an adjustable length checker and based on the pattern the roller tip marks...you'll know whether to go shorter or longer.

 

Stock in what? And pushrod length always has to be checked.