badger, if you can point me toward someone who has mufflers with aspirator tubes in them for a reasonable price...like $100....I'd be much obliged.  

 I haven't had much luck building my own aspirator in a truck muffler.   Filter life without the precleaner approached zero.   Nobody seems to have a 5" aspirated muffler except the OEMs, and they are all fairly pround of them.  Deere seems to be the most reasonable....about $300.