Inline 6 headers installed...Now it won't stay running

[dnorris009]

First, I wanted to say thanks for all the help.
This is a great community, especially for me...the mechanically challenged.

Anyway, My 200 inline chevy never failed to start & idled fine with the stock exhaust manifold. (even with manifold only/no pipe)

Installed the longtube headers & now it refuses to stay running.
If I keep feathering the gas, I can keep it running
but the minute I let off, it dies.

Only thing I've done was change from stock exhaust to headers.
Does going to headers require changing the timing? Carb adjustment?
Something else I'm missing?

Thanks again for any help.
Dave