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5 speed rearend

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v8mgbal

v8mgbal

Jedi Trainee
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Hello all, which rearend is better to use with the datsun 5 speed, the 3.7 or the 3.9 thanks.
 
I'm going with the 3.9 with my 5 speed conversion. Maybe Tervor will chime in here shortly as he has had his on the road for awhile.
Roy
 
I'd say 3.9, especially if you are in the hills. But you have to answer what you want from the car... high speed cruiser? drag racing? twisty roads? casual touring? IMO 3.9 is a nice compromise.
 
thanks trevor, I would say most of my driving is high speed and causal driving with some twisty road sometimes.I am getting a parts car with a 3.7 and I was not sure if I wanted to keep it or sell it.
 
The datsun 5-speed has a lower 1st/2nd, so the 3.7 helps a bit there. If your engine is strong you might want to try the 3.7. That will put you at about 3300 rpms at 70 mph in 5th gear.
 
First gear in the Datsun gearbox is VERY low, I think maybe it was designed for a stump-puller! Again, very low first gear.

3.90 is a nice compromise rear end. IMHO. I've had 3.89s in two GT6s with overdrive and it's almost perfect: great for around town and off the line; but not too low for top end performance.

Let us know . . .
 
Just because you have a 5 speed does not mean that you have to drive in 5th gear all the time. 4th is a 1:1 ratio and will be exactly what the old 4 speed would have been. Mine originally had the 3.9 which I thought was too low and I drove a 3.7 and still thought it was too low on the highway(both with the 4 speed) The way mine is now 3rd is about where my old 4 speed was with the 3.9 and 4th is what I drive in a lot around town and 45mph zones and such and then 5th is a true OD and works well on the faster highways. I hunted for the 3.55 gearset that I have now. VB used to sell it and I guess I bought one of the last ones. I would at least hang onto that 3.7o until you do the 5 speed and see what you want. Swapping the pumpkin is fairly easy if you want to change it.
 
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