A buddies carbed camaro is smoking when hes letting off the gas after the 1/4mi. (low 12sec car) Its a stock rebuild that was done about 2,500 miles ago, and it was not a soft break in. It only recently began to smoke, and is getting worse, but only when he has the throttle blades shut at higher RPMs, it does not smoke at idle from what we can tell, or at cruise, not at start up either.

Its a carbed 350 with stock ported heads where the porter hit the bottom of the stud hole on the intake side. He put #2 sealant on the rocker studs. The heads were also recently rebuilt with new valve guides, and valve job, about 6-7k miles ago, and had new valve guide seals put on when the bottom end was rebuilt.

Could it be an intake gasket letting go? The rings giving way? or the rocker studs, or valve guide seals?

The motor is using/losing about 1 qt every 400miles. Odd thing, is the plugs do not show any signs of oil burning on them, they are a tan with a red spot on the center porcelain. It does have a small leak at the back of the intake, and i think part of the oil pan is leaking in the back. But it does not leave much of a spot when parked, usually 2-3 1-1.5" wide oil spots after a week of sitting.

Any tips on where to start looking and how to correct would be greatly apprciated.