OK, the exhaust in my American is pretty much 100% iron oxide now, so it get's a new poop chute next month. Though it's a typical 3-into-1 iron manifold (two cyls per exhaust port) it seems less restrictive and less angular than the later six (OK the exh ports in the head run nearly 90 degrees...) Question: is there any likely scavenging benefit possible from running something like 48" of skinny pipe (like 1.75") down from the manifold, then dump into larger 2" - 2.25") from muffler to tailpipe? Keep in mind this is a small engine that spends most of it's time 2000 - 2800 rpm (hence the 48" number). Or should I just run "as large as I can get" (say 2.25") from end to end with a good muffler? I'll mailorder one from Summit or somewhere. _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list