I have a 383 in my 68 now with a munci 4 speed and I think Im running 410 or 411 gears. Looking to change then out to 373 or 355 whats the best option? Car is geared way to low now!

It depends on how you want to drive your car.
Do you want it to be the fastest at the strip, get the best mileage, or somewhere in between?
It will also depend on what maximum rpm the engine turns and the tire height you have, as these figures need to be considered also.
A little more info here will be handy.

Car is geared way to low now!

I hear what you're saying.

I had a 4.56 until last Friday.
I went with a 3.42, because that is where I need to be.
3.55 is popular also.
A lot will depend on what type carrier you are running.

Another option would be to install a tremec 5 or 6 speed and leave your rear gears alone. The overdive will be nice on the highway AND you won't lose your performance. Or a gear vendors overdrive unit... you would have 8 gears if you want them !

It depends on how you want to drive your car.
Oh Yeah..
Mine does a heap of highway...100 to 500 miles at a time several times a month, plus a bit around town
350 turbo 308 gears
I would like to drop rpm down on the highway,
If I drop the rear end down will loose the around town traffic, stop start drivablity, plus the torque converter will be always chopping in and out

Been working out stuff here and there over bthe last few months
And considerng this
Drop in a 700 auto..
this will give me lower ratio 1st and 2nd espec 1st...a definate boost to take off
Then the higher (what one could consider and over drive) top would then give me around the 1800 to 2000 rpm on the highway..
Best of both worlds ..but thats just my therory at the moment..
I dont know anyone who has done or got a 700 auto here in NZ..so the conversion, what s involved/cost... still looking into

What u change bet it wheel diameter, diff or trans or combos depends on what yo are using the car for 99% of the time.