I am in the process of installing my rx-7 fashion downpipe. I have everything out and am about to reassemble. My question is chould I replace all the nuts? Only one of my studs came out so I am going to replace that with an alan bolt. Should I replace all the other nuts with new one's? If so what kind should I get?

 

You should replace all the studs / bolts - The heat/cool cycles soften the metal of the bolts allowing them to stretch and/or break when retorqued.
Use high grade steel or stainless, studs and nuts (w/spring lock washers) or hex bolts & washers
Allen Head bolts will corrode from the heat & the head will strip out the first time you try to remove them, unless of course you use SS.

 

Good choice on the RX-7 Fashion DP. Thats the same one I have. You will notice a difference imedeately. lower exhaust note, quicker spool, ect, ect.

 

I got all the studs out, they came out a lot easier then I thought they would. I was woried about breaking them off, so thats why I didn't take them out originally. I think I am just going to use stainless bolts with spring washers. Are there any major disadvantages to this.