Huge flat spot from about idle to 3k under load

I'd reckon carb so don't worry until its on gas. It could be the fuel dropping out due to the cold, but I doubt it.

 

The cooling of the inlet before the S/C doesn't matter so long as the fuel stays evaporated. It gets heated as it gets compressed and pushed out the other side to the motor. That will all vanish on gas anyway.

 

Fun to drive?

I don't think it mixes properly when I turn the car off you can hear the fuel dripping in the manifold so that's gay as

But yes it's fun to drive when it's on boost :)

Cheers miller