I am looking at getting the smarty Jr. Can the stock airbox with a fleetguard filter handle the extra HP or should I spend the money on an S&B cold air and intake to make sure the engine can breathe. Truck is still completly stock

 

Smarty JR's are made for mostly stock trucks.

Mine is fine with a stock airbox and an Amsoil Nanofiber filter in it, with a Maganfow exhaust.

 

I dyno'd next to a guy with the same truck, but a short box. I had a stock air intake and he had an AFE Stage II.. No noticible difference in power.

Run the new double deep OEM filter, or the Amsoil Nanofiber.

 

I still have the stock air box and dropped a K&N in it. The filter has been in there for 2+ years and there's still no dusting on the intake tube. My Smarty Jr. is set on stage 1; that's all the extra power I need.