My Armours two into two pipes didn't fit at all. They would not plug in to the head - dia too large. They suggested that maybe there was some ovality, there wasn't. They suggested that my (iron) head was wrong and that I should open out the exhaust ports. Comparing with my original pipes I found that the originals were very slightly reduced to make the fit.
To be honest the bends in the Armours pipes didn't look very nice either, not properly blended in. I'll not do business with them again.
Lets face it an A10 is not exactly an exotic, if they can't even get that right ... ?