3:42 vs 3:73 gear

[Ridgeline]

I just got a hold of a 8.5 grand national rear end with a 3:42 eaton posi unit. I was wondering if the difference in performance between the 3:42 and 3:73 were worth the price of a new pinion and ring gear? Just plan on doing some in town type racing with a 350 ci 87 el camino.
Thanks.

 

[dan2286]

It depends on what trans you have and if the engine is stock or modified.

 

[phaZe]

If the current one doesn't have a posi, it's worth it. You will decrease top end speed, but will gain torque.

 

[pontiacman469]

Personally i love my 4.10s,3.42 to 3.73 is only one tooth so i doubt it would be that big of difference.

 

[Blake442]

3.42 should be plenty fun, and it won't cost you any money. Not to mention that if you don't have overdrive, it will make highway driving that much more bareable...

So long story short, the difference won't be noticible enough to warrant buying a new ring and pinion...

 

[dogsht]

The only place you would notice a difference is on the highway. You would see & hear it rev harder with the 3.73s. Assuming you have a 3 speed transmission. Also if you race the car with both rear ends on the track you should normally find a tenth by going to a 3.73 but you would not likely feel it with ye old butt dyno. If you have a 3 speed stick with the 3.42, and why risk wear & noise problems for a tiny tradeoff.

 

[Footbrake]

Gears

I myself went from 3.42's to 3.73's. It helped my 60ft. a tad but did nothing for my E.T.'s

 

[megaladon6]

here, play with this http://www.gtsparkplugs.com/GearCalc.html[/url]

 

[midwestls]

cool, another bookmark. Thanks. :lol:

 

[Phoenyx]

3.73s are great. I have them in my car. But if you only ave a 3 speed like me, you can look at abut 3000-3500RPMs n the highway.