I was doing some cleanup on my 69Z28 yesterday and was quite suprised that the bolts holding the bellhousing to the block have a head marking that reads EWF. They are the type that has a built in flanged washer.
I allways thought they were RBW, I never looked that close before.
They have been on the car since i owned it (1973) so i assume they are original. They also have orange overspray on them.

Can Any other TC member comment on these bolts? Thanks.

the ones on my car have like the grade 5 markings with a circle A in the middle.