whoa baby! Rocker bolt stretch

Man. Trying to button everything up today. Everything going pretty good this build, and I run across this.

Torqueing my rocker shafts and things just didn't feel right. Just COULDN'T reach 30 ft lbs. Thought something might be stripping and ran across this.
Check out the rocker shaft holdown bolt on the right. Not a very good pic, but I hope you can see the amount of streeeech. Glad it didn't break. It actually has a "waist".

I think the combination of 565lbs open pressure and the fact that these are probably factory(old) bolts caused the problem. I'm running Hughes 1.6 rockers with their shafts.

Now. Should I shell out for their Billet holdown kit, or just go find some new grade 8 bolts.

Sure appreciate your advice, as always!