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that depends. How much power and what boost level are you running? The factory spec motor is VERY strong. There's a guy on here making 680 HP at the wheels on a factory RB25neo bottom end.

Personally I wouldn't drop the cash on a rebuild until it's necessary

^^^^ this plus, why do you want that power, seriously from a person that keeps modifying, get it solid and drive it...

So man times i have been to track days or a texi and i guy that does better times is std r33 with more seat time...

Yes the economics is fix when it needs to be fixed . The only reason to build a Neo in an R33 block is to keep the original number , if that wasn't an issue I'd look for a Neo engine in good condition and run that - after the 33 engine expired .

Economics should take precedence over ideal unless people like being poor or have too much money to spend .

A .

I think you're missing the point too. No 2 R33 blocks would be expected to have the same sized bores and the same sized pistons, such that you can wantonly swap pistons from one to the other without checking to see if they match. Ever heard of manufacturing tolerances? How about piston grades? F'rigzample.....Nissan would receive thousands of pistons a week into the RB engine assembly plant. These would have all been made to the same spec at the same factory, yet nevertheless, they would have come in a variety of sizes. So they would have been sorted into various size bins, and the smallest ones would have been put into the smallest bores and the largest ones would have been put into the largest bores. There might have been only two bins, there might have been 6, it all depends on how good the manufacturing was and how anally retentive the famously anally retentive Japanese automotive engineers at Nissan were feeling.

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