Hey, you're in Victoria!!!!
My daily driver's starter crapped out. Apparently there was like a quart of oil in it.... And to think, every thousand miles, I was lifting the oil cup cap and putting in two drops of oil... My rear main has leaked since the dawn of time, and right now I'm fixing it in the drive way. You could easily be like me, drop the oil pan and check the clearances with plasti gauge. It's a nice day to do it. I'd look around for a spare tranny, that you could rebuild while you drive the other.
I'd check through the drive line though first. The u joints and such. Maybe it's nothin?
I've always thought I'd have spare parts rebuilt, and ready to go on. However, I've not mastered it yet. I seem to have a number of things that need rebuilt, that have not been as of yet.