taller 3rd & 2nd
 

I am in the process of gear selection for my tranny. I want to use a 3.88 r&p and a .821 4th gear.

Has anyone used this final drive combo ( 3.88 r&p/ .821 4th) with taller 2nd and 3rd gears?

I have found that using a stock 1974 3rd gear going into a taller 4th gear drops into a big hole when shifting into 4th.

Purpose:

I want a taller third to bridge the gap, and make it smoother transition. This transmission is suppose to be for highway driving but not sacrifice bottom end. I am currently using a 1641cc dual carb'd motor, but will be going to a 2270cc T4.

What size are your rear tires?
I have that a trans with 3.88x.82, and with a 24.5" tall tire I found the gearing a little too tall for my 2 liter. When I had 23" tires it was a little too short.
I didn't find the drop that bad. Perhaps with your 1641 you don't have enough power to pull that taller 4th. With your proposed engine, you will have a lot more bottom end torque, so the gap won't seem that bad.
If you are set at changing 3rd, you could go to a 1.21 or 1.19. I wouldn't change 2nd. That gets real expensive ($5-600).

I do not have my wheels yet. I plan on using 18x8 & 18x10 porsche wheels with stock tire sizes, or maybe the 17x7 & 17x9's with stock sizes.

I know the current motor I have does not have the torque I am looking for throughtout the RPM range. But my T4 will.

Thanks for the advise on the 2nd and 3rd gearing.

before you pick your gears, you have to choose your outside tire diameter.

265 / 35 x 18" = 78.5" circumferance with 30% tread remaining on my 18" x 10" turbo twists. :D