Chip,
The stock t/b on an 07 SEUC is 46mm. I have a 62mm HPI on my motor. The motor seems to love it. Everything hooked right up with no issues on the HPI throttle body, including the cruise control.
Scott
Thanks Scott!
An accurate voice of reason.

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Another fact,
My 120B came with a 46mm on it. (I know, it's hanging on my wall)
With that throttle body it produced 108/112T on Tmans dyno.
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My 120B Jim's built 18 months ago has an HPI 56mm T/B with the 4.89 injectors.
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So Ken, what does all that mean?
I think it means that with 5K plus members you may possibly get 5K plus recommendations as to what you need to do.
Try again talking with Jim's for them to make a recommendation as to what to use and or ask them to recommend a builder that has many 120's under their belt to find out what they recommend for a stock 120. You can't go wrong with a proven combination. You just have to find someone who has built some.
Good luck!
Chip