3rd gear whine on 1974 Cologne 2.8 V6 standard 4-speed transmission

[limey222]

I took my vehicle out tonight for a spin and noticed for the first time that I have a whine in 3rd gear on my stock Ford 4-speed manual transmission. Its not really loud but it has me a little worried ....should I be? Are older Ford gearboxes inherently noisy?
I've been progressively driving the car harder as I get more confident in its mechanical condition. I have wound it up to 5K through the gears occasionally, can it take it?

 

[Andy D]

Check the lube level and its color. If it is low, the gears get noisy. I drained and filled the 5 spd while it was out.