I have a '71 240. It has the earlier, stamped-metal cross piece supporting the transmission. On the top surface of this piece there are two thumb-sized indentations, one on each side of the centre mounting bolt-hole. They cover about half the width of the cross piece. So my questions is, does it matter whether these are to be at the front or the back of the cross piece once installed?

Makes sense I hope.

Thanks

The dimples are there to clear the tips of the rubber insulator mounting bolts once the x-member is in place. Put the cross member in place both ways, you'll see the difference in clearance at the tips of the bolts. Other than that, its reversable.