DUALS on a 84 regal

[bar fightin man]

Waddle Doodle

The bolts holding the left end of the crossover pipe on my engine that connect it to the manifold snapped right off in the manifold.

So now I have half bolts ,i guess rusted or really tight, on my crossover and the other half of those bolts, rusted or really tight, in my manifold.

Would it be easier, cheaper, both, or niether to fix this problem to make the exaust system the way it was, or would it be easier, cheaper, both, or niether to make it ready for dual exaust.