1968 z /28 intake bolts

[john302]

just looked at a completely original 68z ,untouched car.The intake bolts are black phosphate.   is this correct?

[Jerry@CHP]

No, that is not right.  All bolts were silver cad.

Jerry

[Jon Mello]

The bolts on my low-mile '67 Z were not plated. I would guess they were supposed to be but maybe they were out of those bolts when the engine was assembled and they used the non-plated bolts. That sort of stuff happens from time-to-time.

-Jon

[JohnZ]

Flint-built Corvette engines with aluminum intakes used black phosphate plain hex bolts; commonly-seen headmarks on untouched original intakes are "A", "NAT", "UR", and "FP", although other have also been seen, and mixed usage on the same engine is common.

[Jerry@CHP]

There are traces of silver cad on both of my survivor cars, the 67 Z (13,000 miles) and the early production 68 Z (23,000 miles).  By pass fitting on the 67 has some orange paint on it and the 68 has no traces of orange overspray.

Jerry

[john302]

THANKS FOR THE INFO GUYS.