Not necessarily but you could afford to. It generally depends on the valve events more so than the duration specifically.

With headers you can afford to run a little bit more advance without fear of the pressure in the cylinder messing with velocity of the intake charge as the valve opens.

 

interesting, so how do you calculate valve events? if companies only advertise duration and other specs

 

You can find websites that will unravel the standard cam specs for you. I made a calculator in excel a while back.

 

I got sidetracked for alittle bit on this. I searched for a 6.0 or 6.2 for a while but never came up with any that I wouldn't have to take out a home loan to afford and for what im doing with this truck I don't want to have abunch tied up in. So Im back on the search.. im thinking the stg 1 cam from tooley is what im going to give a shot. as long as it makes more power than stock I will be happy

 

I ended up picking up a 12 L96 6.0 with the 823 square port heads.. Now im back at it looking at cams and such... Kinda thinking something along the lines of the vinci trucker high lift cam 216/224 .585 .585 115lsa but im not sure still have much researching to do. The square ports are a whole new deal to me..

 

Square ports are a different beast. Those heads respond well to cams that have a lot of duration, yet is still completely drivable.

That cam won't do well in a square port setup.

 

I know they are. Seems they like a good bit of exhaust duration due to the smaller exhaust valves . Im open to suggestions. Like I said im still researching what will work best. I dont want a big cam at all.. the more torque the better. Stock exhaust will be on this truck mainfolds cats and all even a stock converter.