Slant 6 Roller Rocker Arm Vendor(s)

Imagine if your cam had a different profile ground for each cylinder. That is basically what you are experiencing by using stock rocker arms that have inconsistent and inaccurate ratios one to the other. If you think that is good enough for you...fine! Then they will probably not benefit you since you don't see the benefit in what they provide. Unless you sit down and graph the mechanical ratio and observed lift on each rocker arm(which you wont), that is exactly what you will end up with. Roller rockers, since they are CNC machined will have an exact true ratio for each rocker on each cylinder, plus the benefit of friction losses through the roller tips and less tugging on the valve tips. There is 50+ years of proof and evidence of the benefits they provide.

Are they expensive for a Slant....yes, but good quality ones are also for any other engine! Does the cost warrant you buying a set for your application.....only you know that! Are they for everyone....of course not! If your breaking stock rockers now, it can be from several issues. Too much valve spring pressure(even the cheap Crane aluminum ones have a maximum spring pressure recommendation before you have to step up to a better one), mechanical interference such as coil binding the springs. Poor rocker arm geometry from excessive head and block milling but not correcting the pushrod length. You can even have piston to valve contact slight enough to break one, but not drop the valve. Being diligent with your builds in checking all these possible issues can help. But more than likely, you've just exceeded the limitation of the rocker for your application.