ticking in exhaust pipes???

Hello everyone i have one for you all.Last yrs 78 400 before i spun what i think was a rod had a ticking in the exhaust pipes didn't think about much because i had another 400.So the next 400 78 was rebiult and screams runs great but lately i noticed ticking in pipes again?(all new dauls)seems to tick when i'm comeing off idleat 20-25 mph?what is it thought maybe a valve but heads checked good so???what gives anybody have a clue thanks.  

Do you have headers or manifolds.

If you have manifolds some had a butter fly style flap that can make this noise.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

headers and it feels like the ticking is under my ass!hear it sometimes not?  

Have you check to see if the flex plate or torque converter bolts worked there way loose.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Nope but that's a good idea i'll check it tomarrow have some other people's car to work on so i'll check it.It seems to tick when cruzing and let off gas.last yrs 400 had the same so i wonder if that motor is good?Going to put it on the stand and check bottom end.the current 400 it comeing out as soon as i can stop driving it!LOL.Thanx i'll check it out.  

No problem buddy.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

I've had ticking sounds too that turned out to be silly stuff like the torque converters plastic dust cover bent and touching the flywheel teeth. Or the heat shield over the starter loose and clicking against the motor. Or,the shifter linkage where it attaches to the frame wiggling with a loose washer or something.

Sometimes it's such a simple thing, but maddening to locate. The last time I rebuilt a 400 I was ready to tear it back apart because water was bubbling up from the heat exhaust crossover vents on the manifold. Then one of the old wise Pontiac guys I know said "probably just rain got in through the scoop." (it was)