[Giller]

There are a fair number of folks out there who have changed out the IMS AFTER finder metal debris and have lived to drive another day. Actually, many many days.

Roll the dice, take your chances. You got the car on the cheap - worst case, you put a few bucks into a fix, it doesn't work - take it as a (hopefully) fun learning experience and then either go get another engine or a newer Box.

Either way, good luck!