Vince in my opinion i would think you could get a little more run time out of your motors...
maybe change some valve springs at 150/180 passes..keep the pressure knocked off them in the off season.
perform a compression check on each cylinder..if it still reads good...then run it...this is my take..
i assume when you re-freshen one your motors your only replacing bearings,rings,valve springs....
and of course as long as your car is still running the numbers before you tear it down..
i have seen mild conventional head motors run over 300 passes with only a valve spring change...
this is only an opinion tho..
Brian
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Bjuice..
"I'M YOUR HUCKLEBERRY ! "