Does anyone know how much HP the stock 48mm throttle body will support? The reason I'm asking is because I'm still running the 48mm TB on my fairly warm 350, and am wondering what I'm leaving on the table. Last time at my local 1/8 mile track, I was running consistent 8.1's N/A. :rockon:

 

I don't know.

However, I doubt it is holding you back very much. It is of course impractical to buy a bigger TB and install it and test it. However, it is NOT impractical to buy a TB airfoil to see if the increased flow yields noticeable gains. I would pop in a TB foil (many on ebay) and see - if you notice a gain at the track, then that is very telling.

 

At least 510 HP. The GMPP RamJet 502 makes 510 HP with a stock dual 48mm bore throttle body (from an LT1). It might do better with a larger one, but that's the HP rating.