Buying new buick

Ive owned a 98 &a 96 buick 3.8 & 3100 both had the problem with plentum or anti freeze getting into engine what year buick would i have to buy not to have this problem again /

Buy one without a 3.1 or 3.8?

Next question.....

Buy one that's already been updated with the new gaskets.
If they can't verify the gasket change, knock $750 off the purchase price.