could the intake be holding my low end down?

do a compression test;
130psi will have a soft bottom,especially with a stock TC
140 less soft, wakes up later in the rpm scale, still works with a 2500 to 2800TC
150 now yer getting somewhere, plenty of torque at stall.
160; now yer risking detonation, have to run premium, and usually, the 360 will be a ripper.
And make sure your timing curve is decent.

I've run 3 intakes on my 367 and altho I currently run the AG, none of them were slugs....... but I run around 180 psi, what a ripper of an SBM.
edit:(aluminum heads)