True 8 Gage banana plugs

Use naked BFA style. they will take full diameter and make better connection with your female binding post. That is all I use.

Use 2 or 3 layers of heat shrink to make a gripping location.  

why are you using 8 gauge? seriously over sized for the use.

your not welding with them are you? you do realize its probably 18-24 gauge on the other side of the binding posts, both ends......

your not pumping 40amps into a speaker are you? 

This occurred to me; internal wiring is much smaller. However, my run from the amp is long and I have five drivers on each channel. It already sounds better. Good point, however. 

These are what I use and they work great FURUTECH FT-212(G) hi-performance Gold-Plated/Pure-copper Banana plugs-set of 4 | eBay

Check any of the Furutech banana plugs they will take up to 5.5mm wire diameter, which is around 4 ga. so 8 ga. wire is an easy fir in the Furutech banana plugs either straight or 90 degree also the 90 degree plugs spread open when you tighten the screw so that they stay tight in your amp or speakers.

they are somewhat expensive but your get what you pay for, they are top quality plugs.FP-202（R）/（G） | FURUTECH