What's the best way to flush out synthetic redline fluid?
Trans slips more than i like even with upgrades. I've read some bad things about using synthetic.
I already removed the pan and took the valvebody out, but now there's the converter full of fluid.
thanks.

 

the fluid is not to blame
Your slipping is not caused by the fluid...swapping to type F is not going to magically fix your issues

BUT...if you want an old trick we used at the Taxi Cab shop, to drain converters, you can drill a 1/8" hole in on the pump side of the converter between the fins to let it drain...if you're careful there will never get any shavings inside
Then to close it up, an aluminum pop rivet works great

Can't tell you how many taxi cabs had that done to them during regular service to make sure as much of the trans fluid as possible was drained.

 

I read this - https://ls1tech.com/forums/automatic...uid-4l60e.html
If I add standard dex3 with a little synthetic is it going to hurt anything?

 

if you have dex6 now...pouring in dex3 is not going to fix your issues

The only way it would...is if you were low on fluid level and you refilled the trans properly and got to the proper level with dex3...then it might help something

but to answer your question...dex3 and dex6 mix just fine