What is the correct part number for a 70-71 E-body shifter boot (with console if that matters)?

I have two with the same part number (3467770). The tall one is very hard and not pliable, the shifter frequently pops out of third gear.

The shorter one is unused NOS and is much more flexible. Do they stretch out and get harder with age or is that a variation in vendors?

A lot of the repros I see appear to be tall. Any recommendations for a good reproduction?

Thanks