My truck: 1973 620 L16 SWB A/T
My Trans: Jatco 3N71B
My Rear end: 4.625
Been researching the "620 5 speed swap." datzenmike has been a godsend in helping to understand this whole thing. Here's where I'm stumped.
What is the "ideal" 5-speed to differential gearing for daily street performance. By "daily street performance" I mean, quick take off when the light turns green, quick through gears, and a comfortable drive in the HOV lane for an hour+ drive. Something that's fun to drive.
Please assume that the L16 engine is just fine...built and tuned for street performance. (it's not a 1.8 or a 2.0 so please save the "you should have this xyz engine instead" comments for a different thread)
I've heard that the '80-'83 280zx non turbo close-ratio gearboxes paired with a 3.54 rear differential is "what everyone wants." Is that true? If so, what is the benefit of this pairing as opposed to others? Are there comparable box-to-rear end parings that are good for our little trucks?
datzenmike has generously explained how the mid-ratio 5 speed gearboxes would best suit my current 4.625 rear end. Is there a better (or rather, ideal) rear-end gear ratio for the mid-ratio boxes for daily street performance?
To sum it up:
Which is mo' betta for a fun, zippy ride: a close-ratio with X.XXX rear end OR a mid-ratio with X.XXX rear end?
Thank you, in advance!