Have bee reading as much info as I can find ,On blown motors the usual is 32/36 weber or 350 holley. What size carb for my A14 S/C engine. The motor is fully rebuild with all stock internals (arp rod n head bolts, magnafluxed crank,shot peened and polish )at 8.5cr. Wad cam is 1009A. H89 head all cleaned up with mild porting. Blower is new eaton A45 twin screw. I am figuring on 8psi boost limited to around 7K rpm. I like the sound of these 38/38 webers, I think their around 390cfm. I know both barrels work in sync also.So my question would this size weber be over kill ??

I can't see that being overkill. That cam should also make power beyond 7k. Very keen to hear how this thing goes. 7 psi would be going very easy on it.

All the best with it.

Will a top hat covers clear/fit under a 1200 bonnet ?

Were you going to blow through this carb on the standard manifold??? Or if you are mounting the carb as draw through on the blower, only you can answer this question.

blow through on standard manifold.

Top hat takes less room than a stock air cleaner. So unless you are mounting the carburetor extra high, there should be no problems.

Sikyne...So how many psi can I go with stock pistons , will I have to run a intercooler over 7-8psi and how many rpm will a 1009a Cam allow me to go ?? Is there a performance manifold that is available other than a standard one?? I have the cam specs here but they dont give me a rev range. As I do not want a hand grenade but reliability. Also, with the extra torque Im hoping for, can I drop my diff ratio from 4.11 to 3.7 without sacrificing too much acceleration and give me better legs through the gears. I will be running a celica box with has a shorter gears than the datto's to begin with .