Standard bore is indeed 3.875"! Most pubs round it up to 3.88", including Chrysler's/Jeep's. The metric specs are rounded to a single decimal -- 98.4mm x 87.4mm -- which comes out to 3.87401575" x 3.44094488", so you're correct in surmising the stroke is close to 3-7/16". 3.4375" is 87.3125 mm, so it's a bit larger than 3-7/16", but not 3-1/2" (88.9 mm). 3-31/64" seems to be about right in English fractional units... ------------ Date: Thu, 14 Aug 2008 13:56:23 -0400 (EDT) From: adh@xxxxxxxxxxxxxxxxx (Sandwich Maker) I still wonder if the 4.0 isn't -really- 3 7/8" x 3 7/16" - 3.875" x 3.4375" -- Frank Swygert Publisher, "American Motors Cars" Magazine (AMC) For all AMC enthusiasts http://farna.home.att.net/AMC.html (free download available!) _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list