Q: Under the hood of my Ford Mustang II King Cobra II is the original 302 bored .030 over.
It has flat top forged pistons, Sealed Power chromoly rings, a reconditioned .020/.020 crankshaft, performance reconditioned rods, high-volume oil pump, a Summit cam with new lifters, matched valve springs and locks, Summit pushrods, and a double roller timing set.
The heads are 1970 351W with new valves, hardened seats, a three-angle valve job, and COMP Cams Magnum roller tip rockers.
The timing is set at 10 degrees initial and 32 degrees total.
At idle, I have the idle screws all the way in, and the engine will not shut off and runs very rich. The carb has a 4.5 power valve with a vacuum gauge, and in gear it has about eight inches of vacuum.
The car has been sitting for about eight months with 90 octane treated fuel.
Could the fuel be bad? Do I have the correct power valve? Got any other ideas?
A: We believe your power valve is correct.
Your problem is probably carb-related, though.
We recommend disassembling the carb and checking all of the passageways in the baseplate and metering block.
Also, check the main body for obstructions in the air bleeds and the small holes at the bottom of the casting.
If this doesn’t turn up anything, try adjusting the secondary butterfly angle.
There’s a small screw located on the bottom of the carb near the secondary shaft on the passenger side. Turn this a half-turn in to open up the secondary butterfly a bit.
This will allow you to close the front throttle blades some, which will give you more control from your mixture screws.