Yer bud is stepping up to the 306 cam, so there is a bit more stress the springs and rockers will go through. The valvetrain, which is always under load, will have some flexing going on and will worsen (load) the higher the rpm, based on whatever seat pressure u have and valve springs . This flexing is not always good. It will invite improper timing and a load of other issues: ie...spring failure/rocker stud/rocker failure due to valves bouncing off the seats. Given this, it's always a good idea to improve the strength of the valvetrain by stepping up to larger diameter studs, quality rollerized heavy duty roller rockers with h/d trunions with guide plates and stronger pushrods for insurance. SA rockers are good units but do have limited high rpm capabilities.....some of us know this because of broken valve springs/ rocker arms...hehehe So given the above, either rocker will work, just depends how high yer willing to rev the old LT-1 in search for more power up top....