Im about to get a Skunk2 IM for my GSR with I/H/E, I was wondering if i should go with a aftermarket throttle body right now or keep the GSR throttle body on the skunk2 manifold?. If i should get another throttle body what size should i get?, and also what size is the STOCK GSR throttle body?.

 

you arent going to be using the IM unless you have aftermarket cams in your head that are opening the valves further and longer for more air to flow through the head. Without that, your engine isnt goint to suck anymore air in than it normally would. Aftermarket throttle bodies are pretty expensive, I would suggest that you take your gsr TB and get it bored out to 64 mm.