You Provided Lots Of Details, But Left Out An Important One.
It is most desirable to have the alignment done with fresh tires, properly inflated.
I’d get the tires and immediately have the alignment done . . . unless the alignment shop is 100 miles away.
That’s what you left out. How far will you be driving between getting tires and getting an alignment?
And another detail was missed. You wore tires out in 6 weeks, but the information needed here is not the number of weeks, but the distance driven on those tires.
I’m curious. How many more miles or years are you planning on running this 91 Grand Voyager?
CSA