450 starter 420 car

[kyrin]

seems the starter in my daughters 420 is actually from a 450
it has been working for more than a year when it stuck an hour from my house
pulled the starter off and there it was a starter from a 450
so my qeustion is should i leave the starter in and shim the bolts so it will not jam? it was wedge in there in the first place
i know it worked but are these two starters dramatically differant in anyway where even if its put in right it will jam up?
i know the right thing to do is buy a starter but she's a college student and the budgets tight
thanks