| 3.419" = 87mm Condition of cylinder walls dictate what will be needed for you in terms of pistons. If the cylinder walls are in ok shape you can run the 87s but you'll absolutely have to have the block honed to get the corrected P to W clearance set. As it stands Nissan did very minimal clearance for the cast pistons in the block. Going from a cast to a forged piston will yield you having to increase clearance due to the expansion rate the forged unit will grow into. In my experiences its easier to step up to a .5mm or .020" larger piston which would go from your stock bore of 87mm to an 87.5mm. Discuss your needs in terms of what the engine will see usage wise with your machinist so he can appropriately set your P to W clearance with the new forged pistons. The spec sheet that comes with the Wiseco pistons is a SUGGESTED ***MINIMUM*** clearance that does not mean its where the piston should be set to in terms of overall bore clearance. Its the starting point. If you plan to joy ride and put some good miles/power through the assembly you should dicuss that with your machinist. Be sure to use a tq plate and DO NOT have him hone without one. Variances I've seen throuhout the years without a tq plate being used has been from a mere .001-.0023" mis-shapened bore or completely out of concentrically.
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