440 source ductile adjustable rocker arms.

My 68 383 4 speed GTS was the most fun car I’ve ever driven or been in. You’ll love it.

Regarding the 440 Source rockers, I’ve got nothing. They have been a wonderful contributor to our hobby, and they have made it better. That said, I would view any new, unproven, low cost product with some skepticism, no matter who is offering it. In the case of rocker arms, maybe consider a lower cost product that has been time tested.

Good luck.