Where did you get yours from in the end?
I'm having serious difficulty getting exactly what I want. The plenum bolts are the hardest to source.
I've got two options
1 : go for aluminium and get them anodised
2 : go with pro bolts and pay a fortune
The main problem is getting all the required bolts under one roof, in the right style.
For instance I can't seem to source a M6 x 70mm in a flat Allen head. I can get normal Allen head but not sure they would be suitable for the plenum?
I got them from Pro-bolt, they have since gone back though as the heads were too small, just waiting on my refund. Search their site though (if you haven't already) as they do have a big selection, I just told them the style I wanted and used Chilli Red's engine code the set they had made up. I didn't want the plenum ones as I've polished mine (was easier and cheaper).