Hi all

I'm looking at making a frame for my motor bike. It's a section that bolts onto the main frame and supports the weight of the rider and exhaust. It is held onto the bike via 4 x8mm bolts.
Around the head of the bolt there is not much gap between bolt and the main frame. So I am worried it would not have enough meat to support the weight. Any advice please.
Any advice of how much this would cost to produce?