Throttle Body size 52mm or 58mm?

**97ramair** · 11-25-2007, 02:04 PM

Can anyone recommend which throttle body to use on an LT1 motor with headers, exhaust, computer mods, K&N, 4:10 gears? I plan on one day purchasing an intake manifold. Thanks!

**Y2KPewterSS** · 11-25-2007, 03:52 PM

52mm

**fast93ta** · 11-25-2007, 04:50 PM

52mm you cant put 58 on stock intake. but if your planning to get new manifold soon then it would save money to just get the 58 mm then get your manifold.

**97ramair** · 11-27-2007, 05:47 PM

Thanks, but what if i plan on getting a new intake manifold? Is a 58mm still 2 big?

**Firebirdjones** · 11-27-2007, 05:51 PM

No it won't be too big as long as you get the manifold for the 58.

What he meant was the current stock manifold you have will only support a 52mm.....thats as large as the openings will allow.

**97ramair** · 11-27-2007, 06:10 PM

Thanks guys!

**Olde Skoole** · 11-27-2007, 06:24 PM

None of those mods are gonna cause the engine to exceed the maximum air-flow rating of the stock Throttle-body.
The engine needs more air to make more power, which it will after sliding in a Comp HR275
Then you can justify the larger throttle-body and a FAST Intake.

**BlackLT1Z28** · 11-27-2007, 07:11 PM

So far, your mods don't warrant the need for the 58mm. However, if you are planning bigger mods in the future and want a new TB now, save some money and get the 58mm now. You'll have to get the manifold ported to match the 58mm though.