Does anybody know what the max MPH 3rd gear will go in these cars?

around 115 limited
on a NA model, aerodynamics limit you before gearing does IIRC

So would it be safe just to keep it in 3rd all the time, because my overdrive is WEAK.

dont you have the selector for D instead of D with the circle around it? that will keep you out of OD

i have RND321, if i leave it in drive it will automaticly go into overdrive, im just asking would it hurt the tranny driving in 3rd all the time.

I know when my pcm was stock 102mph was all I could get in 2nd gear. That being said I think the L36s are limited to 108mph so I would guess that would be all you could get without an aftermarket pcm or wheel/tire changes.

Ed

You'll get worse gas mileage leaving it in 3rd.

Maybe we should troubleshoot your OD? What do you mean by 'weak'?

Why'* this in performance?

When im in overdrive im cruising at 1,500 to 1,800 RPM and i have pretty much no acceleration or passing power.

Does it not downshift when you push on the gas enough? Leaving it in 3rd will seriously affect your gas mileage at crusing speeds.