74 dt 250 fresh bore 71mm Wiseco kit piston and rings. Does anyone recommend ring gap tolerances?

I'm sure Wiseco does.

If its been bored to the right clearance then the rings supplied should have the right gap, or close enough not to have to worry. Hold it up to the light & can see the gap--my rough method-- but get the rings square on checking one at a time fitted in the top of the freshly bore cylinder & push it in square a little way using the piston crown.

Early Wiseco pistons were like many racing pistons that came with tight gaps that had to be filed to size. Not paying attention to ring gap on those contributed to the "seize-co" nickname due to running with little to no ring gap.

Modern Wiseco now come with rings with bigger gaps out of the box.

If you can't find the Wiseco spec... it will be in/on the box or on their website, (IIRC, Wiseco often gave ring gap spec in terms of so many thousandths per inch of bore)... you can use the Yamaha spec which is in the manuals available here.

& make sure they bore it to wiseco specs not yamaha specs or it's likely to retain its seizco nickname