i got the ams downpipe and it rubs a little. I do have the spacers from buschur but i need longer bolts. Anyone know the thread size or bolt size???

come on someone has to know

What is a "Lower Tie rod"?

he is talking about the 2 braces that go under the DP.

Go to Lowes or Home Depot witht the bolts with you. They have a large display on a wall that has thread sizes and pitches for a reference. I THINK but am not sure tho that they are 8x1.25

+1. take the bolt with you, find a nut that fits it, and then use that nut to find a longer bolt.

10x1.28 pitch.
what you want is 10x1.28x30mm length.