Im going to change my 10 bolt open rear for a 12 bolt posi and i'm trying to get an idea as to which tires to go with. The tires on the car now are on 15" rally wheels and it seems like they are very short for the rim, can't recall tire measurement off hand.
They only measure 24.5" from the ground to the top.I plan on installing a 3.73 gear and would like to get an idea as to what you guys have on those rims.
Anyone running the 3.73? Tire size? RPM?
I have the gear/RPM calculator

http://www.drivetraindirect.com/html2/calculator2.html

And it's pretty helpful but I wanted to get input first hand. Oh yeah, Car is a 396 w/T400 trans.


Thanks in advance for ANY input, Harry

Originally posted by ACLineman:
Im going to change my 10 bolt open rear for a 12 bolt posi and i'm trying to get an idea as to which tires to go with. The tires on the car now are on 15" rally wheels and it seems like they are very short for the rim, can't recall tire measurement off hand.
They only measure 24.5" from the ground to the top.I plan on installing a 3.73 gear and would like to get an idea as to what you guys have on those rims.
Anyone running the 3.73? Tire size? RPM?
I have the gear/RPM calculator

http://www.drivetraindirect.com/html2/calculator2.html

And it's pretty helpful but I wanted to get input first hand. Oh yeah, Car is a 396 w/T400 trans.


Thanks in advance for ANY input, Harry What year is your car? 15 x ??? size ralley? I've got 15X10 ralley replicas wrapped in 275/60 BFG rubber on my '71 'Velle. Some guys have 325/50 on their 15X10 rims...everything depends on what look you're going for, and how th car is going to be driven. Good luck with choosing the right tire graemlins/thumbsup.gif

Car is a 69.

Rear rims are 15X8 fronts 15X7

Not TOO concerned with the width although it will be a factor.
How "tall" are your 275/60 BFG what kind of gear and tranny are you running and what's the RPM @ say 60 MPH ??

Hi Harry,
Haven't seen you post in a while.

Anyway, on my 68, I have had, 275/60/15 BFGs on the rear, and if I recall correctly, they are about 28" tall, with all kinds of clearence.

I've never had a rub even on twisty roads, with 4 adults on board, and 2 of those adults were 245lb plus.

The front I've run 215/60/25.

I've run these tires on 15x8" rear and 15x7" front ralleys, and currently run the same tires on 15x7" torque trust Ds.

My RPMs are about 3200 at 70 mph, but I'm running a 4 speed and 4.10 gears.

I run 17" rims but my overall tire height is 25.7". In 4th gear with 3.08 I spin 2500 at 60MPH. With 3.73 and 24.5" tires that thing is spin to the moon on the highway. Hope the bottom is in good shape.

I run 305/45R/18's at 28.8 inches tall! :cool:

Originally posted by ACLineman:
Car is a 69.

Rear rims are 15X8 fronts 15X7

Not TOO concerned with the width although it will be a factor.
How "tall" are your 275/60 BFG what kind of gear and tranny are you running and what's the RPM @ say 60 MPH ?? They're 28" tall, I've got a TH350, stock rebuild with a B&M shift kit, 4.11s out back, and I believe at 60mph I'm right around 3,000-3,200rpms..not too sure, my speedo doesn't work right ;) ...it may be higher, cause it seems like when i'm "cruising" on the freeway at 3200rpm, everybody's passing me up, I gotta take it up to around 3500rpm, but, then I start passing everybody up tongue.gif

LXS,
How do you handle that Motor screaming, "SHIFT!!" :eek: . I have a th350 with 255/60/15 with 3.55 Eaton Posi and I have to turn up the radio or something cuz it gets old pretty quick! I couldn't even imagine 4.11's. Some long trips on the freeway and I about want to eat my gun graemlins/clonk.gif JUST KIDDING.
My next upgrade on the chevelle will be overdrive, ok if my wife let's me :D

later, graemlins/thumbsup.gif

Hey Thad, !!And Thank You again Redrum for the Yoke....Your The MAN !!

I have been busy and with no garage :mad: and cold A$$ winter,The chevelle has been in storage and not much thought has gone into it.It was 58 yesterday and I fired it up and took it for it's first drive in 4 months graemlins/hurray.gif
Guys were bowing as we drove down the street :cool:

Anyway I over the winter I found a 12 bolt open rear and plan on scraping my open 10 bolt (does anybody buy these things?)and setting up the 12. The short tires have to go too
(I plan on donating them to the asphalt) HeHe

I was curious as to what some of the other guys here had on as far as rubber and height.

On the gear calculator if I go with 3.73 and 27"tires @ 60MPH, RPM should be 2785. On the other hand if I go 3.55 gear,28" tires,60MPH,RPM would be 2556.
This is GREAT stuff.Guess I have some decisions to make.

PS, How do you guys post links (pictures) to your cars next to your signatures?

go to your profile and in your sig box just type the address exactly, and will show up as a link in your sig line.

Originally posted by ACLineman:
PS, How do you guys post links (pictures) to your cars next to your signatures? Harry,
If your like me and don't maintain a web page,
the best thing to do (in my opinion) is join Team Chevelle as a member.

Its only 20 bucks for the year, and Al or Dot will set you up with a showroom you can download your pictures to. graemlins/thumbsup.gif

Thats the way I do it anyway. :rolleyes:

Guess I should get up off the wallet....I don't have a web page and don't know too much about these here computer thing a ma jigs !!!

What are some benifits of joining such a prestiges club??

Hi Harry, on my 72 Chevelle I have a mild 350 (around 345hp) a TH350 with a transgo shift kit and a 12bolt posi rear with 3.42 gears and 275/60 tires, With this combo I can cruise the highway at 65mph at 2600rpm. I think 3.73's will work fine, you will probally be around 3000rpm at 65mph with a 275/60 tire. If I was able to have a second chance I would go with the 3.73's since I don't drive on the highway to much, but since theres only around 8,000 miles on my new gears (formerly 2.73's graemlins/sad.gif ) I won't be changing them anytime soon. If it ain't broke don't fix it, right. ;)

Originally posted by ACLineman:
Guess I should get up off the wallet....I don't have a web page and don't know too much about these here computer thing a ma jigs !!!

What are some benifits of joining such a prestiges club?? Some of the parts places (Ground Up etc.) give a 10 % discount,
you get a little flag by your name,
and access to the members sections (not a big deal) but sometimes guys will help you find stuff you need,
you can post for parts wanted, and if somebody sees it they may contact you.

I look at it like the best magazine subscription you can get.

Originally posted by tdjr66:
LXS,
How do you handle that Motor screaming, "SHIFT!!" :eek: . I have a th350 with 255/60/15 with 3.55 Eaton Posi and I have to turn up the radio or something cuz it gets old pretty quick! I couldn't even imagine 4.11's. Some long trips on the freeway and I about want to eat my gun graemlins/clonk.gif JUST KIDDING.
My next upgrade on the chevelle will be overdrive, ok if my wife let's me :D

later, graemlins/thumbsup.gif That's a very good question, and all I can say is lucky you, at least you have a radio graemlins/clonk.gif ...lol sometimes it does get a lil annoying, can't drive down a quiet street without having the whole neighborhood running outside their house thinking it's an earthquake :eek: ...but, then again, there's nothing like driving and hearing nothing but a sweet sounding motor, cam buming, and knowing all those hondas or whathave you don't have a thing on you graemlins/thumbsup.gif ...and honestly, I thank God I got those 4.11s, because they've really helped me drive "normal" on the freeway. A couple years ago, I used to be one of those idiots racing on the freeway, thanks to an open rear and 2.73s, but, not to justify my actions, I didn't do it in peak traffic hours, it was done between 11pm and 2am...still not smart, but those 4.11s have held me back and made me realize how dangerous and stupid freeway racing was and is!