Power loss. 318 Vs 340 manifolds

does your tube point forward before it makes it's way back. Ive seen 340 manifols that point straight down close the the fire wall, mine points forward toward the front left then the pipe has to be bent to go backward. I think I found a solution from TTI, The Head tubes for $178 + shipping.

Are you running 2 drvs side or 2 oass side manifolds?