Based on my BMW bike building experience: we ran a 94mm bore with a 45mm in. // 40mm ex. valve set up as did the BMW Roadrace of Butler & Smith Inc.: 2.02 = 51.308 mm 1.73 = 43.942 mm 1.70 = 43.18 mm 1.60 = 40.64 mm 1.50 = 38.1 mm 1.406 = 35.7124 mm [ 327cu.in. is 101.6 / 3.25" stoke - same as NASCAR -] =Bt= milnersXcoupe "The Heretic" [ Double-click this line for list subscription options ] I've been looking at valve choices. 4.0L looks like a very interesting possibilty for valves and ofr real irony the cheapest place I have found new valves is HESCO!!! Go figure! I'm not settled in on that valve choice yet though. Doing the math if you add two cylinders to a 4.0L it comes up to 322 cu in! Pretty darned close to a standard bore 327! But I'm not positive that the 4.0L valves are perfect. The exhaust on the 4.0L is right in the 1.5" range head, larger than the 1.406 of the stock 327. But Chevy 1.60" valves are easiliy available and a real close match too. _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list