lol 10 bucks says the rattle he hears is an exhaust leak around the header

 

I know I have an exhaust leak but this sounds nothing like an exhaust leak

 

its your timing, It just happend to me when I advanced it,its the same sound your describing,I just back the timing down a hair,I didnt use a timing light though. I backed it down till the rattling noise went away,but now I'm back where the timing was.but thats ok I wouldnt want to blow my engine.

 

Lowered the timing, Put seafoam in it..and higher octane still making the rattleing noise.. now that I listen it acutally sounds like its comeing from underneath..more towards the front.(cat location)

 

you still have stock cats? they're probably junk. the honeycomb inside is rattling around because its broken apart. lay under the car and tap on the cats with a wrench or small hammer, you'll reproduce the noise almost perfectly if the cats are the problem.

 

maybe its his motor mounts, they could be lose?

 

motor mounts generally cause a vibration or ton's of body flex, not really rattles

 

I know its not the motor mounts...Im afraid to go banging on the cats, dont want the sound to get worse lol...

 

jack the car up and bang on your converters with a rubber mallet and listen, also check the welds on all your cats shields and any traces of black carbon from the exhaust indicating a leak.when mine did that, I looked and seen someone put a rag in between a heat shield on the converter that lost two of its welds to rust.

I wouldnt drive

 

What you mean you wouldn't drive? The sound doesnt seem to be as bad anymore, I messed with the timing more then gave a couple taps on the cats. Still makes the sound but very little. I only hit thecat on the left side so I think it may have cleared that one up(for now lol), Cause you can hear the noisemainly just onthe right now..so guess its those.