Transmission / Shift Linkage: No reverse, and a question
 

I have a five speed tranny from an '83 that works fine, except that it won't shift into reverse. I pulled the back third off, and realized that I can manually move all three of the shifting "F"s that stick out from the gearbox up and down. This means that it's definately a linkage problem. Now, there's three "F"s and a single backwards "L" attached to the shifting rod that fits inside them. I am assuming that, since only one of the three "F"s can be up or down at a time, the "L" is catching on two of them when I try to put it in reverse. So, I figure I'll grind a little off the inside edge of the "L" to let it go through.

The problem is that I don't know which "F" is which. I don't know if reverse is up or down, the bottom one or the top one. If you do know, please give a reference as to what you consider to be the "top" and "bottom" of the tranny. If anyone has any other thoughts or suggestions, please let me know.

Thanks.