<VV> GL4/5

[Paul]

I've followed the ongoing conversations regarding GL 4 vs GL 5 with 
great interest. Unfortunately, it's a bit too late. I filled the gear 
case of my 66 4-speed with Amsoil which "meets specifications for GL-2 
through GL-5". I thought I noticed more difficult shifting, but chalked 
it up to my imagination. Now I'm pretty sure that I want to go with a 
pure GL 4. I installed a plug in the molded-in  boss (like the 65's 
have), so draing is simple. My question is "Do I have to flush out the 
old stuff, or is it sufficient to just drain and refill?"

Paul
65 Corsa