Looking for some info, what tire package do I need to get the most rubber under the front of a '97 Park Avenue.

The car has traction issues now that will only get worse with the intercooler. . .

I am looking for a total package, rims and tires. I would prefer DOT, but the PorkAve will not really be a daily driver so if I end up with race tires thats not a deal breaker.

245 maybe 255?

I ran 245 and had room, 255 should still fit. It'* going to come down to the offset of your wheels.