Rear gear advice

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Robb

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Looking for advice on rear gear selection. I have a line on an open 8 3/4 rear with 3.55 gears for sale, but I am unsure if 3.55 is the right choice for me. I have a mostly stock 340 and I am currently running 215/70/14's (would like to go wider in the rear). I only drive it on the street and do a fair amount of highway running at 65-70 mph. It wont see much abuse, but I want something stonger than the current 7 1/4, and I don't know what gear is in it now...

Advise on changing to a 3.55? I may be able to get a 3.23 from the same guy, but not sure yet...

Thanks,
Robb
 
I say 355 is a great street gear, has enough get up and go, but not too crazy for long drives...
 
Thanks... Any info on what RPM range I would be running at 65mph? Also what height tire would help change the ratio?
 
I'm a little different. I like the 3.23. It is a great all around gear. I have had 3.55s and 3.23s and there's a pretty big difference, especially on a long drive. The 3.23 difference is, you need an engine with a lot of torque to pull it and make it work. For a small cam 340, I think the 3.23 would be a better choice. The small cam means that the torque peak will be down low to pull the gear off the line hard. I personally think you'll get tired of the 3.55 on long highway drives. But what do I know?
 
i agree with stroker 323 is a preety good all around gear that break your pocket book on gas & keep the rpm's at a minimum
 
If the rear is a good deal I say get it. A-Body 8 3/4 rears are hard to find these days. I have 3.55 gears in my Duster & I plan to use 28" tires which will give me 2747 rpm at 65mph. Here's a formula to use. 65(mph) X 3.55(gear) / 84(28" tire diameter X 3) =2747. There's always the 8 1/4 rear as an option.
 
Thanks all, I originally thought it was going to be a 3.23, but it turned out to be 3.55. Now that you mention it....What would be a good price for a for a complete non SG 3.55 a-body rear? I live in Cincinnati it location matters...
 
For a non sure grip I would spend around $100-$150 But that's just for the pig. If it is drum to drum $400 to $600 or more now-a-days.
 
3.23 is better if you'll do a lot of freeway travel, 3.55 if more around town/sportier driving is your desire. I'm running 3.55s in both of my cars but their play things.
 
Robb said:
Thanks... Any info on what RPM range I would be running at 65mph? Also what height tire would help change the ratio?
Click to expand...


65 at about 2750RPM with 3.23's

and 65 at about 3000RPM with 3.55's

Thats with the tire you have now. A taller tire will lower the RPM down a bit your close to 26" tall now.
 
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