"The inlet throttle butterfly is 55mm in diameter, and will flow more air than any amount of power that you can get out of the 4AGE with the factory inlet manifold, so there is no need whatsoever to fit a larger one, as some people do. I have seen a report on a dyno run that shows an engine with a 60mm throttle body fitted - ~20% more throttle area - making about 1 - 2hp more, which is more likely to be dyno error than anything else."

i was just reading through bill sherwoods page and this got my attention so i thought i would chuck it hear!

i spose if you want to flow more air for N/A, get quads. for turbo i spose the bigger the better!

im using a large FJ20 item for my silvertop turbro.