Perfect example of electrolysis. Kinda unusual for it to happen there.
there is a bolt size thread in the technical/how to threads.
since there has been plenty of talk... and no doing it... intake manifold 5/16-18 x 2.5 valve cover 1/4-20 x 1 Crank pulley 3/8-16 x 1 Plugging Smog Hole (thermactor plug) 5/8-11 speed sensor clamp 1/4-20 x 3/4 Tps sensor screws M4 x 0.7 pitch x 25mm length intake plaque 8-32x1/2" taper seat...www.stangnet.com
The stock strut sometimes has a cap that has been riveted to the top of the cylinder that is larger in diameter than than the cylinder itself. The problem that it causes is that the coil over sleeve wont slide over it.
It has happened to me on almost every single C/O kit I've purchased. The remedy is to grind down the overhang so the sleeve will slide over.