Single-pattern camshafts (equal duration) work fine and make great torque but work best on engines that have heads with good flowing ports on both sides and non restrictive exhaust systems, the dual-pattern camshaft (split duration) increases scavenging and is better suited to operate in engines with restrictive exhaust ports and/or exhaust systems.
The stock SBF head with its weak exhaust is best suited for a dual-pattern grind along with a well designed non-restrictive exhaust system to increase velocity and scavenging but if aftermarket heads are in the plans along with a dual-pattern camshaft then be careful not to 'over-build' the exhaust so as to prevent or at least minimise over-scavenging and killing the torque.

 

how so ?
when do i know is to much,, adding long tube headers 1 5/8",,, 3" collector and a cross over into single high flow muffler with dual exhaust.

i'm in the middle of my 351w build gt40 heads 64cc , 12cc inverted dome pistons .030 0ver, Typhon lower - upper intakes, Crane cam 444232, 1.725 rockers, 70mm TB. 92 ford f-250

I did send the Typhoon lower & upper intakes back to china due to very poor workmanship and quality control.

I did buy Edelbrock #3887 as the replacement made in America by Americans

 

. Your combo should work fine with that mild 206/214 Crane cam, ~9.5:1, and 1 5/8" long tube headers...

 

Well, it's not like a stock SBF head is real strong on the intake side either.

The flip side is you could port the snot out of a pair and it wouldn't make much difference below 3,500-4,000rpm. A cam with 206° duration on the intake side will fall flat pretty soon after that anyway. A good breathing set of heads might extend the top end ~1,000 rpm.

 

thank you for the input