Exhaust - What to do???

[davidimurray]

When you weld up a collector, you normally bring the pipes together, tack them so they all touch - then make an infill piece to cover the gap between the pipes where they join and weld that in. You then slip the collector over, and weld all around the outside of the pipes. This should then give you a full sealed collector.

This will explain it better - http://www.coneeng.com/weld_on_collector_kit.html

but instead of having the merge bullets you fill the gap with a bit of flat plate.