I am no expert here but I believe I have an exhaust leak. At least it barely sounds like it when driving. What is the best way to determine if there is one, and best way to find it? Are there any common areas for exhaust leaks on 68 327's?

My 70 Chevelle had an exhaust leak at the heat riser valve. Replaced it and it was good as new.

Thanks in advance!

One way is to have an assistant place their hand over the tail pipe exit and you listen for the leak, the rushing of gas from the leak.

Usually, the heat riser will leak at its shaft if original system, as shown in your signature. Nice find.

I take a piece of heater hose and cup my hand around one end and hold it up to my ear. Then move the other end around the ehaust manifold or pipe and it really isolates the location of the sound. It has never let me down. Good luck. T

Great method DTB, I'll give it a try. Sounds like a sure fire winner.

The heater hose method works great. Put a piece of tape around one end of the hose and always put that end to your ear. It keeps you from walking around with a gob of grease in your ear!

I have a Chambered system, that has been leaking at a couple of the joints. Is there something to apply before putting them back together, that will stop the leaks? Or do I just have to tighten the clamps tighter?

If it is in an area that won't show, you might try the black High Temp permatex. I've used it before with problem headers and gaskets. It holds up pretty good. Put it on, then let it set awhile 'til it gets kind of rubbery wet
then don't over tighten. Hope it helps. T