i have an L98 350 with the stock 3.27 with a 9-bolt. i was pretty much wondering if anyone got a gain with putting different gears in their cars. i don't want to go up to a 3.73 because the car already has too much low end for street tires. i don't want to be buy slicks due to the stress on the drivetrain. right now i am running lower 14's with some bolt ons. i was thinking a gear around 3.45 or so since they make those for 9-bolts. also, how would your rpm's doing at highway speeds over the stock 3.27's?? i am mainly looking for a little more midrange and highend without harming the launch too much. any suggestions??

 

just put slicks on it with the auto you will be fine, heck the 9 bolts are stronger than my 10 bolt I pull 1.63 60ft's with, plus I know of guys who run 1.5X. I would keep the gear thats in it if it was me JMO.

 

Like Funina said, keep the gears. 9-bolt gears are mad expensive anyway.
-Rippin

 

3.27 is a pretty good gearing for TPI...you could go to 3.45's but for the cost it's probably not worth it. You'd be lookin at $300+ for the gearset, another $100 for the install kit, and then the cost of having it all installed. With such a small change in ratio the gains would barely be noticable.

 

The diff between 3.27 and 3.42 aren't enough to justify the cost of putting gears ina 9 bolt....If you think the car has too much low end for street tire then I suggest moving your HP up the RPM band as much as possible by getting short runner SLP runners (siamesed) and cutting the plenum to match....or maybe a stealth ram for the maximum effect, but I don't know how much motor you have that might be a bit much, but GMHTP in the steath ram install said that the car lauched much easier, even though the SR had more potental to make power, since the SR moves the torque so much farther up the RPM band

 

I agree with these crazy guys too. Keep that gear unless you want to want to make it a strict track car AND you want to get MUCH stickier tires, as in Slicks or ET Streets AND you are planning on a better/higher revving intake like the StealthRam.

Unless I said I did 3.73 gears in my last TPI 350 car and it launched VERY hard but it fell on its face way too early, even for a TPI long tube intake runner system. 3.23 or 3.42 gears would have made the car quicker in the 1/4 mile but slower in the 60 foot.

Now I have a 305 with a carb/carb intake and 3.73 gears and it seems more at home in it's powerband compared to the 350 I had. The Powerband has much less low end torque and more top end. This week I did a MUCH higher stall converter too which helps even more and I am running a 10" Et Street too Hopefully it gets quicker and quicker.

Goodluck! I mean...Goodluck hooking that torque monster to a track as it is and hopefully you find more HP in the future.