54 Chevy rumbling sound

I have a stock 54 chevy with the stock drive line. Car has 70K on it and runs good with fentons and a couple of coils cut out on the front. After I installed the fentons and gl*** packs I noticed a rumbling sound when I put it in gear. It starts when I put it in gear but goes away when I give it the gas. It's not bad or anything but never noticed it before. It drives smooth down the highway but at stop lights it makes that rumbling sound not so much a vibration but a rumbling sound. (No not the mufflers) Seriously I'm a little confused as to what it might be. Surely it's not a u joint or it would do it when moving. Anybody had a similar issue?

 

Muffler or pipe could be rubbing on something under the car. Look it over and see if any part of the exhaust is to close to the frame or anything else.

 

Naw I don't think thats what it is but I will look to be sure....

 

sounds kinda like your exhaust is sitting on something at idle but moves away when you give it a little gas,does it only do it at idle? you could have a ****** or motor mount going bad .

 

Also check to see that your exhaust has either a rubber strap or rubber mount holding it up and on, no place for a solid mount.

 

Good input. I'll check Thanks.

 

If your hangers are solid straps, they're transmit vibration to where they're attached.

The exhaust may also hit somewhere once the car is down on all fours, if you can get it on an exhaust rack, run your hands between the floor & pipes to check for clearance.

Bob