Small Block Intake

Many years ago I built a 340 that got put into a lil red express truck.
I used a std Performer on it.
It had no problems pulling to well over 6k.
It was slightly over cammed for the rest of the combo.

A few years back I freshened it up.
I put a little smaller cam in it when I did....... a Comp 268H.
That improved the seat of the pants low/mid feel in the truck, but it didn’t have as strong of a top end rush........ but it was a better overall package.
It still goes to 6k without any protest though.

You say you bought everything matched for the cam......

The question I have is....... did you buy springs for the aluminum heads, or springs for stock heads?
The installed height between the two is quite a bit different, and springs for stock heads, installed on aftermarket aluminum heads, would have low pressures, unless someone specifically addressed it.