Replacement Powerflow Manifold to Riser Gasket Early Style Round Hole
These are all the popular IMCO riser gaskets Don't be caught without spares
This is a common wear item.
Replacement Powerflow Plus Tailpipe Gaskets (Sold as Each)
Replacement Powerflow Plus Manifold to Riser Gasket (Each)
IMCO Manifold to Riser Gaskets - Replacement Thumper Power Riser Seal