Not sure if you saw that the motor he is asking about putting in is not a low rpm torque build, "Looking at a drop in ready 465 HP / 494 FT LBS engine." It's a relatively high rpm build that puts out well over 1 hp per cubic inch at well over 5000 rpm. Stock manifolds are a serious restriction on a motor like that. They are going to kill off quite a bit of power.
I agree that if he chooses a lower rpm, stump puller type 408, he can get away with those restrictive stock manifolds and have a much happier, more tractable street build.
