Date: Wednesday, March 14, 2007 11:32 AM From: milnersXcoupe <hh7x@xxxxxxxxxxx> "The 4.0L has a 0.125" larger bore and the block is about that much wider on the right side (87-90 258 blocks use the same outer casting and are also wider)." Swygert, Francis G MSgt 436 CES/CECM As to the inner castings, since the cylinder locations are same as the 4.0 > are the cylinder walls thicker since the pistons on a 258 are smaller diameter ? ----------------------------- As far as I know the walls aren't thicker, the water jackets are wider. No point in wasting a couple pounds of good casting iron for nothing! _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list