The 292,s are very troublesome with exhaust manifold leaks when used on heavier then 1/2-3/4 ton trucks. It is probably leaking between the manifolds where the intake & exhaust bolt together. It probably has the 2 1/2 in outlet manifold that the outlet points straight down. The light duty manifolds won,t fit. You might check with a GM truck parts dealer & see if a new one is available, although I dought it. If you take them apart it,s very likely you will havev to replace it. They run extremly hot.
