I hope that guy on youtube wasn't breaking in the engine!
I run a 70 type 429 Dove heads etc, with a 280 Comp cam, 10-1 comp
why and intake and headers in my 57 and am pleased for a street motor.
I did put guide plates, adj rockers and hardened pushrods. I didn't like the
way the roller rockers rode on the valve stems so didn't use them.
It doesn't run 11's like the ole 427, but it runs good.