Finally decided on a cam for teen SB. Should I bother with header?

TrailBeast said

I don't think any stock bottom end 318 ever made 320/350 without being sprayed or boosted.
And I know for a fact that 020 off the head of a stock 318 still didn't.

Heck they only had 180-210 brand new with the two barrel and a four barrel isn't going to give you another 100-150.

Just sayin.

Click to expand...

The 318 did come more powerful than you listed and pay attention to the increase head size and noted porting if the head and manifolds. Though he leaves the pipe size out. The slightly increased cam size is also a split duration and adds to the extra effiecient engine breathing. While not big, it doesn't need to be.

Again, I do think it is a bit high of a est., some facts remain uncovered.

Take a look at the broom stick cams used in 300HP engine!

The stock bottom end only lacks a piston tall enough for a decent ratio.