SB intake

Peak will be down, torque band pushed lower but also fall off faster..like 4000rpm and fading fast.
Most would barely catch full advance being they wer known to stretch into 4ooo rpm with the stiff springs they used.
Most of it is the plenum..but the runners are also pretty pinche..
We know the ultimately it is a flow limited manifold byproduct of the small runners enhancing the velocity to increase such torque or Aid in it. So we could safely say that you may as well run a 273 manifold if you want just a little bit more RPM/power
I mean if you line them up and look them over there's definitely a pecking order.
The 273 four-barrel manifold does not do a lot when it comes to the flow bench...but it's enough to make 290 hp...hence the 235hp 273 once the cam and carburetor come into play....knocks off another 30 or so cfm 'restriction and less than peak flow [email protected]'.

I put the 256 or 258? 4 brl , by itself,onto a ported 302 head at 202cfm... and it knocked it to 145cfm.