More than likely, on your exhaust, you are missing some of the studs for it...this is a common occurence on the high strung S14. Instead of studs, you can get allens to put in. It is kind of tough to install because of the limited space allowed. The rear seal, you should get the seal, there is a metal plate too...you may as well also get the shifter shaft seal (I believe thats what its called.) If you have mechanical knowledge, these should be DIY jobs. Sorry I cant get into too much detail because I havent performed the tasks on my car as of yet.