Do I want overdrive?
1 - 20 of 23 Posts
Joined
·
881 Posts
2.73 gears? what do you want OD for??
i have 4.11 with a build 200-4r and love it. best of both worlds.
its a 10 bolt and getting tired when i get ther 12bolt im thinking 3.90 to kinda split the 3.70 - 4.11 - my idea of compromise lol
i have 4.11 with a build 200-4r and love it. best of both worlds.
its a 10 bolt and getting tired when i get ther 12bolt im thinking 3.90 to kinda split the 3.70 - 4.11 - my idea of compromise lol
Joined
·
8,058 Posts
not much advantage with your current rear gear ratio = with an overdrive transmission you might want your effective gear ratio in overdrive to be in the 2.41-3.23ratio range. you are already in that range. for a street car i would leave it alone unless you want to change rear gears and install an OD-trans to get your overall/effective gear ratio back to the range it is now:thumbsup:
Joined
·
3,204 Posts
Yes!
A 200-4R or 700-R4 would provide wider 1-3 ratios. Those work better with a 2.73 gear in a lot of cases than the TH350 ratios. I'd take either over the TH350. As for 4th and 2.73s, it's not going to be the hot ticket for speed, but if you need highway mpg, it would work.
Would I do it? Yep. But eventually I'd go for a 3.42 or 3.73 rear gear.
Would I do it? Yep. But eventually I'd go for a 3.42 or 3.73 rear gear.
Joined
·
3,204 Posts
Exactly what I paln on doing this fall as well.
Joined
·
877 Posts
X2. I have the same setup in mine. If you do the math the final drive ratio with the 4.10 in OD is 2.75, almost exactly what you have now but the real advantage, as chevyefi already mentioned, is in 1st thru 3rd. I run 2,400rpm at 70mph on the highway. If you keep your current 2.73, OD will drop your final down to a 1.83. Unless you have tons of low end torque it's going to lug so bad that you'll never use the OD. I had an `83 GMC pickup years ago with that combo and the only way it would even stay in OD is if I could keep it above 80mph, and even then it had to be on a straight flat road with a tail wind behind me.
700R4 or 4L60e?
Joined
·
196 Posts
I have 3.73 gears. And ran a 4l80e for 2 years, manual valve body and a brake.
But when i am on the street ,i run 31 inch tires.
The only time i have ever used over drive, was the day I tested the lock up converter, then I never used it again lol .
Since then I took that heavy pig out and now run a M21 .
What size tire do you run? with your 2.73 gear?
But when i am on the street ,i run 31 inch tires.
The only time i have ever used over drive, was the day I tested the lock up converter, then I never used it again lol .
Since then I took that heavy pig out and now run a M21 .
What size tire do you run? with your 2.73 gear?
I have a similar setup, but instead of the TBI I have the 5.3 (LS Platform) I am running the 4L60E with the 2.73's and love it. Granted I went with an 1800 stall converter because I had absolutely no bottom end. But being a lock up converter THATS where I got the best of both worlds= higher RPMs at low end, and LOWER RPMs at top end. On the freeway doing 70 somewhere around 1800 RPM. I have driven from 60 miles north of Fresno (where I live) to LA area twice with it, and to north of San Francisco 4 times with it. All 6 trips I was getting 25mpg WITH A/C. I wont ever look back on THIS car for the drivability.
Maybe another car Ill build one that is higher in RPM and power, but this is a car I wanna be able to put my 5 year old and wife in, go cruise for longer drives and not have issues.
Maybe another car Ill build one that is higher in RPM and power, but this is a car I wanna be able to put my 5 year old and wife in, go cruise for longer drives and not have issues.
And I have a LS1, and a 4L60e and new gas tank with pump inside.
I know wiring is a big deal, that is not what stopped me.
When I found out I would have to get a new gauge package and it's associated wiring, I froze. :sad:
So I found an easy fix, 1993 350 TBI engine and my old TH350.
I know wiring is a big deal, that is not what stopped me.
When I found out I would have to get a new gauge package and it's associated wiring, I froze. :sad:
So I found an easy fix, 1993 350 TBI engine and my old TH350.
Please explain that sentence.
Thank you,
Charles,
Your 2.73s are a nice highway gear. However for quick acceleration/drag racing many think they aren't as good as, say, 4.10 gears. Guys who use 4.10s and similar miss having a highway gear for cruising. The OD trans gives them an extra gear above drive to lower RPMs/fuel consumption on the highway. The only good reason for you to get an OD trans is if you wanted to swap your axle gears to something stouter like 4.10s etc. Hope that helps.
Your 2.73s are a nice highway gear. However for quick acceleration/drag racing many think they aren't as good as, say, 4.10 gears. Guys who use 4.10s and similar miss having a highway gear for cruising. The OD trans gives them an extra gear above drive to lower RPMs/fuel consumption on the highway. The only good reason for you to get an OD trans is if you wanted to swap your axle gears to something stouter like 4.10s etc. Hope that helps.
Joined
·
2,315 Posts
X2 on what Ron said. :yes:
The goal is gas mileage!
Stock 1993 350 with added 4 bbl, stock 1970 Chevelle body and suspension, stock 2.73 rear gears.
Now running stock 1970 350Th transmission and have a stock 1993 700R4 in the shed!
For highway mileage; say Charlotte, NC to Wisconsin Dells, and later this Summer; Chicago to Santa Monica, will the 700R4 do me justice or will it hurt the engine?
I have after market cruise control.
The long trips this year are Hot Rod Power Tour and Route 66 end to end.
Stock 1993 350 with added 4 bbl, stock 1970 Chevelle body and suspension, stock 2.73 rear gears.
Now running stock 1970 350Th transmission and have a stock 1993 700R4 in the shed!
For highway mileage; say Charlotte, NC to Wisconsin Dells, and later this Summer; Chicago to Santa Monica, will the 700R4 do me justice or will it hurt the engine?
I have after market cruise control.
The long trips this year are Hot Rod Power Tour and Route 66 end to end.
Joined
·
881 Posts
You wont hurt the engine...unless your going drive it around lugging. 2.73 w/ .70 OD is about 1650rpm @ 70mph.
will depend on the cam too.
Drop it into 3rd 1:1 @70 and your at 2200rpm... with like 27" diam wheel/tire
will depend on the cam too.
Drop it into 3rd 1:1 @70 and your at 2200rpm... with like 27" diam wheel/tire
Buick roadmasters in 92 came with a 2.73 a 700r4, and a 10 to 1 tbi 350 with cast iron heads. There were some complaints about spark knock, but premium gas solved that. I had an 81 Camaro that I put a 700r4 in with a 3.08 gear. It was great, but I think a 3.42 is a better all around gear behind a 700r4. I also believe that a 700r4 is a more efficiant trans than a turbo 350, because of the vane type pump. I had a Plymouth Duster that had a 727 and a 2.45 gear& a 360. It got 12 mpg on the highway. I changed the gear to a 3.21 & the mileage didn't change. The mileage went to 10.5 when I rebuilt the engine, bigger intake valves more cam ect.Then I put a 700r4 in it & the mileage went to 15.1 mpg. I have pics & details on my website.
1 - 20 of 23 Posts
