Ok so at getting a new throttle body but dont know what to get, 70mm or 75mm. The only other mods I have are JLT CAI and an off road x pipe, but i plan on getting more bolt ons in the future but dont know what throttle body size to get, and im getting the matching intake plenum with it.

 

research both 70 and 75mm and see wich one is for you I did and decided to go with the 70mm setup also found out that you should change plenium with throttle body one time. american musle sells combo kits pretty good prices. I found out that when n/a you loose some hp and tq in the low band of the rpms but gain in the high end. so its what you want from it.

 

If you are short for cash (Lord knows I've been there) get an aftermarketplenum first, as you can see here (my reformatted version of Accufab's flowbench data), the OEM 65 mm TB on all but the C&L plenum (the C&L did not do well overall) will outflow even a 75 mm TB on the stock plenum.[/align][/align]Putting a bigger TB on the stock upper plenum will gain youabsolutely nothing...[/align]

 

Go with the 75mm. Try and get the combo kit with the plenum.

 

WOW...thats some good info cliffyk!

Sounds like Plenum and 70mm is the may to go.