crusin92red5.0

is a 75 mm throttle body too big? i'm about to do a HCI swap (probably trick flow top end kit) and rebuild the bottom end. should i get a 75 mm bbk throttle body? a guy locally is selling it for 100 bucks? should i get a 70 mm? thanks

Ridinsidewayz

The 75mm may be larger than nessesary. If your looking at the trick flow top end kit I'm pretty sure the manifold intake is designed for a 70mm. They make a track heat kit that excepts a 75mm, but I think it costs a little more which will defeat the saving on the throttle body.

1992lx5.0

what you really have to look at is the long run picture like your plans down the road, i run a 75mm on my 306, i have an f cam, stage 3 afrported heads, 24lb injectors, 80mm mass air, 255lph fuel pump i just upgraded this week, msd 6al ignition and right now i have a gt40 upper and massly ported lower, soon to be going holley system max... just to name a few things,but i did all these mods with a goal in my mind of running a supercharger...

so realisticly for a street car with mostly stock parts including h/c/i i wouldnt go any higher than 70 unless your going to have a sick stroker motor or a blower a 75 is mostly over kill for most stangs

WhiteWindsor

Who ported your stage 3 AFR heads and what are the flow numbers?

95greengt

if you are planning on doing future mods which may require a 75 then go for it im runnin a 70 on a stock hci and have had no problems with it

1992lx5.0

a local machine shop hes a good friend of mine there he doesnt do much head work only for certian peopleon the border line of beingjunk im gonna buy the bigger series this fall,

1992lx5.0

ill find the flow charts have to look threw the tons of paper work i have here