Well the topic says it all.....right now I have 2.73's and they suck how many rpm's will I be turning on the hi-way....figure around 70 mph...........Thanks Guys

 

Depends on what transmission you have.

 

With a 700R4 and a 26" tire, you'd be around 2400 RPM with the converter locked up, which is pretty reasonable. The same car with a non-lockup TH350 would be abour 3500 RPM, which starts to get on your nerves after a while.

 

You can calculate your new cruise rpm yourself.
Just divide the rpm you cruise at now by your present gear ratio
and then multiply that by the new gear ratio.

Present rpm / present gear ratio X new gear ratio = new rpm

I have 4.10's and 26" tires and cruise at a cool 2200 rpm in overdrive.... (60mph)

 

It won't be too bad, use the calculator on the homepage to get the actual rpm. I go to college about 3 hrs away. Over the summer I took several trips there before the gear swap and had 2:73s. I would do 80-90mph no problem, now that I got 3:73s I probably only do about 70-75, I don't like cruising above 2500 rpms.

 

3.73's are nice, but, I think even with overdrive a daily driver shouldn't go lower than 3.55, especially if frequent freeway driving is in the cards. That is just my opinion. A 3.06 low and 3.73 rear gears would make for some mad burnouts though!

 

The L69 cars came with 3.73s... lots of otehr cars through the years have had 3.73s and no OD; I've had Chevelle SS396s, all kinds of Z28s, etc. that came that way, with either a T-350 or T-400 or a 4-speed.

 

I dont like them (edit: sold) I dont think it would be too bad with a lockup 700r4 or 5speed or city only driving but get up on the highway with a th350 in front and whhoooohhhhh sounds like it got B,FMudders on it. IMO 3:42 is the only way to fly. I just did some swapping a month back last thing to change was 2:73's to PT/3:42's and the difference was like night and day performance wise.
SSC

EDIT: If you want some 3:73's dirt cheap look for non 4x4 S10's mostly blazers, I found quite a few 3:73 s10 rear ends when I had my blazer and internals are the same as fbodys.

 

ok i forgot , when counting the teeth , how do you know what you have? great tip on the s10 stuff!!!

 

Be aware when I switched from 3.23 to 3.73 my car slowed down. That is why I run 3.23. But if you have a 305 then I say 3.73 and the high speed cruising will be only slightly effected. And 82z how can a higher multiplication ratios produce "better burnouts?" I sometimes do mine in second for obvious reasons.

 

Count the ring gear teeth and pinion teeth, divide that number then round it off.
SSC

 

You don't have to count the teeth. GM stamps the ratio on the
ring gear. An example is: 41:10 which is 4.10 to 1 ratio

 

Thanks for all the help guys!!!!!!! 3.73's are the way to go for me!!!!!!!!!!!

 

How much are ya selling them for SSC?
I might be interested.

Andrew

 

I Should have edited that out, I got tons of emails concerning that. I sold them saturday morning for $50 through the local paper. Yes $50 I hated them that much.
SSC

 

I have had the whole list of gears....I am on my 4th one this year. I have very bad luck......mysterious bad melted roller bearings and thrown c-clips. Anyway, I found the 3.42's to be the best all around. I can still clean up on mustangs and I laugh at the ricers(I am a ***** too so I can say that). I found that the 3.73's Killed my gas mileage a bit too much and it promoted more wheel spin than anything. I also found the notorious vibration problem came about 140 - 150 Kph. Which is cruising speed for me

You can't go too far wrong with either though. What do you do more of...highway or city?