Ok, your car is going to shake a little bit anyways, its a 90 degree V6 block. There is a ballance shaft over your oil valley to help dampen the shaking, all V6 stangs shake. 99+ model V6 stangs have the ballancing shaft to help with this problem. If it is shaking more now then it did when you first got it then it could be due to a slight missfire or possibly a small leak in your head gasket.

Being over the internet there are too many questions to be asked and its too hard to determine if your car might be experiancing the first signs or breakdown or if its just normal. So I cant make any accurate decisions because of that. Just go to your local dealership or trusted mechanic and ask them to do a routine check on your car and tell them about your concerns.

As for your tips, 4" would not make a difference, especially screw on types, kudos for taking them off, they dont ever look good.

Good luck Mike.


-Eric-

P.S. Sorry 99saleen351r, I have that affect on alot of people