Is there really a big diff between a truck
87mm t/b and a 90mm LS3 t/b
on a 2011 6.2 L9H with a cam and LT headers
4" CAI. is it worth swapping to it ?

 

From what I have seen, the intake itself is much more of a restriction than the TB itself. But going to a ls3 or fast intake is expensive and will sacrifice low end power. It would be great to see 1 or 2 truck style aftremarked intakes. We need our power at low rpm but shouldn't have to sacrifice power at higher rpm. It's not like we are trying to turn 9k rpm.

 

The nnbs truck intakes, rectangular or cathedral, mast cant improve on, had that conversation with them when i was building my 99. As far as the throttle body if you have a 4" intake and maf tube, it certainly wiuldnt hurt, generak consensus is better throttle response, but minimal gains, however if you are in need of a throttle body they are typiclly slightly less expensive than the truck tb, or same price!