just curious on recommendations for the throttle body needs for my 6.2L (L92) Sierra Denali Whipple build. Truck has the stock 87mm and I am just wondering what people are running with their FI builds? Will a 90mm LS3 be efficient? Or do I need to go bigger? The truck will be running around 12psi boost

 

Bigger is better for a blower, but your stock one is just fine for that level.

 

Okay, I have a line on a LS3 90mm TB, I'm just wondering if it's worth going all out on big boy 102mm for the build? I'm aiming for 12psi outta the whipple, but may push it to 14psi with an OD pulley. I don't want to have any restrictions on the TB side. And will a LS3 90mm and or the 102mm be a straight bolt on to the whipple?

 

To expound on what Atomic said, I fabricated a new inlet housing to install a 102 on my old style Whipple running around 10 psi. Going from 75mm (75?) to 102, I gained about 1-1/2 psi with no other changes. I can't see you getting that much improvement going up from 87 mm.

 

Yep, if you're gonna use a blower that "sucks" on the TB, buy the biggest you can afford/fit.