I am a regular on Corvette Forum but I need a couple LS1 questions answered. I am putting a custom EFI intake on my L98 Corvette that uses an LS1 style throttle body. I am making an elbow to adapt from a carb flange intake to an LS1 style TB, similar to what Edelbrock makes but mine needs to be of custom measurements.

Could anyone tell me the bolt hole size and dimensions of a stock LS1 throttle body, with respect to the inlet hole? I am planning on using an 80 or 85mm aftermarket but the bolt holes should be the same.

Also, is there any issue with sealing off the back of the throttle body and only having a hole for the intake inlet? For instance there is an inlet for the PCV system and IAC valve that go through to the back of the throttle body. Does the IAC valve opening need to go into the plenum as well?

Thanks

 

Honestly, I wouldn't take anybody elses measurements as a fact. Exspecially since you are going to be fabbing this up yourself. It would really suck to be 1/8" off everywhere you know. I would just buy the throttle body yourself first that way you can fab it off the specific tb that your using.

 

That's a good point he made. Buy a used one for cheap to use for mock up.

 

Thanks for the input guys. Thats probably what ill do.