Transmission help
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 2,193
Likes: 156
From: Navarre FL
Transmission help
I need a little help with some info on a transmission. First off, I have a 78 that I am redoing. It will be getting a late model small block (383) and I would like to swap to a manual transmission. I found what looks like a good deal on a super T10 but want to be sure I wont have problems. So directly from the ad, he is what he has:
THE NUMBERS ON THE CASE ARE 1304065903 WG DIV FPC, SIDE COVER 1304097901, TAIL HOUSING 1304066901. IT IS A 26 SPLINE INPUT AND 32 SPLINE FINE SPLINE OUTPUT
He says it came out of a 1980 Vette, so I imagine all should be good. But I just want to double check with the experts. Any way to tell from this what ratio it is?
THE NUMBERS ON THE CASE ARE 1304065903 WG DIV FPC, SIDE COVER 1304097901, TAIL HOUSING 1304066901. IT IS A 26 SPLINE INPUT AND 32 SPLINE FINE SPLINE OUTPUT
He says it came out of a 1980 Vette, so I imagine all should be good. But I just want to double check with the experts. Any way to tell from this what ratio it is?
Intermediate
Joined: Nov 2008
Posts: 40
Likes: 0
From: Gig Harbor Washington
I would consider going with a 5 speed instead of a 4,With a lower 1st gear ,you might not have to change rear end gears, i changed out my auto for a 5 speed and I love driving the car now.
Safety Car
Joined: Jun 2004
Posts: 4,372
Likes: 223
From: Beecher Illinois
For what it's worth, the close ratio trans in my 79 L82 has........
1304065903 W.G. DIV.
on the side.
I'd have to dig through some more pics to find other numbers, or take an actual look see under the Vette.
Also, MOST stock 78 L82 automatics had the 3.55 rear gears while both the close ratio and wide ratio manuals had the 3.70 gears.
The L48s had 3.08 with auto and 3.36 with the wide ratio manual trans.
1304065903 W.G. DIV.
on the side.
I'd have to dig through some more pics to find other numbers, or take an actual look see under the Vette.
Also, MOST stock 78 L82 automatics had the 3.55 rear gears while both the close ratio and wide ratio manuals had the 3.70 gears.
The L48s had 3.08 with auto and 3.36 with the wide ratio manual trans.
Last edited by KapsSA; Sep 22, 2010 at 02:32 AM.
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 2,193
Likes: 156
From: Navarre FL
I would love to go with a 5 spd. Its just cost prohibitive right now. At $500 for this trans, its doable. And I would rather a 4 spd than a auto.
But I guess what Im getting at is I dont understand enough about gears to determine if I may end up with a problem there. Its getting a 383 with about 425hp so it will have plenty of power, but I dont want to lose all of that through gearing. I also dont want to be redlining just to cruise at 70mph!
KapsSA, if thats the number on the casing on the bottom, then I would say the 903 means you have an alum casing. If its on the side I dont know, could be something with the ratio? this one has 903 on the casing, telling us its an alum case ST10. Numbers ending in 901 on the side and tail. Im not sure if that is anything to do with the ratio. Can you confirm what the other numbers are on yours. that may help us out some.
Whats the worst case scenario here? If my car has the 3.08 rear end and this trans is close ratio? What if its wide ratio?
But I guess what Im getting at is I dont understand enough about gears to determine if I may end up with a problem there. Its getting a 383 with about 425hp so it will have plenty of power, but I dont want to lose all of that through gearing. I also dont want to be redlining just to cruise at 70mph!
KapsSA, if thats the number on the casing on the bottom, then I would say the 903 means you have an alum casing. If its on the side I dont know, could be something with the ratio? this one has 903 on the casing, telling us its an alum case ST10. Numbers ending in 901 on the side and tail. Im not sure if that is anything to do with the ratio. Can you confirm what the other numbers are on yours. that may help us out some.
Whats the worst case scenario here? If my car has the 3.08 rear end and this trans is close ratio? What if its wide ratio?
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 2,193
Likes: 156
From: Navarre FL
Also, my car is (or was anyway) an L48. This tranny came out of an L82. Here is what I get when I plug it into a calculator:
Constants were 275/65/15 tires and 6000rpm red line
3.08 rear end
Close ratio - 72
Wide ratio - 61
3.55 rear end
close ratio -62
wide ratio - 53
Am I going to notice a huge difference between these setups for in town driving? Id like to have the ability to be a hooligan once in a while
I just dont have enough experience with this to know how these numbers will really effect the butt dyno. Obviously a 3.08 rear with a close ratio will feel less acceleration than a 3.55 with a wide ratio, but will it be disappointingly so? Do these numbers make sense to anyone?
Constants were 275/65/15 tires and 6000rpm red line
3.08 rear end
Close ratio - 72
Wide ratio - 61
3.55 rear end
close ratio -62
wide ratio - 53
Am I going to notice a huge difference between these setups for in town driving? Id like to have the ability to be a hooligan once in a while
I just dont have enough experience with this to know how these numbers will really effect the butt dyno. Obviously a 3.08 rear with a close ratio will feel less acceleration than a 3.55 with a wide ratio, but will it be disappointingly so? Do these numbers make sense to anyone?
Drifting
Joined: Jun 2007
Posts: 1,404
Likes: 1
From: Ansonia/NYC CT
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Drifting
Joined: Jun 2007
Posts: 1,404
Likes: 1
From: Ansonia/NYC CT
Stick with he auto til you can get a 5 speed. There are a TON of variables, here.
I have a wide ratio with a 3.08 rear, L48 with new intake, vortec heads, headers and exhaust, and a decent cam, but it's a bit of a dog. I figure based on what others have told me that I should have roughly 315hp to the rear wheels, but it doesn't feel like it.
It's no enough to just have a 425hp motor...where does said motor make that power? And does that sync up with your tranny and rear gear combo? You don't want to redline in highway traffic (like I do), but you also don't want it to bog off the line (like I do, lol).
I too wish I could get a 5 speed...but my corvette funds have been spent for this year. Maybe in another year or so...
In the meantime, don't do a "quick fix" that you will likely not even be happy with anyway. Patience wins the day, you know?
While saving for that tranny, try to find some other small improvements you can make in the meantime.
I have a wide ratio with a 3.08 rear, L48 with new intake, vortec heads, headers and exhaust, and a decent cam, but it's a bit of a dog. I figure based on what others have told me that I should have roughly 315hp to the rear wheels, but it doesn't feel like it.
It's no enough to just have a 425hp motor...where does said motor make that power? And does that sync up with your tranny and rear gear combo? You don't want to redline in highway traffic (like I do), but you also don't want it to bog off the line (like I do, lol).
I too wish I could get a 5 speed...but my corvette funds have been spent for this year. Maybe in another year or so...
In the meantime, don't do a "quick fix" that you will likely not even be happy with anyway. Patience wins the day, you know?
While saving for that tranny, try to find some other small improvements you can make in the meantime.
Drifting
Joined: Dec 2002
Posts: 1,946
Likes: 28
From: Long Beach CA
If I'm following this thread right, you're looking at a 383 stroker motor, a close ratio 4-speed, and a 3.08 rear end. I had something similar in a Camaro -- a close ratio 4-speed and a 3.42 rear end with big tires. The disadvantage of that combination is that it takes a lot of clutch slipping to get away from a red light. The 383 makes a lot of torque down low, so you won't have to do as much clutch juggling as you would with the L48. You'll just have to decide if you can live with it after you get it together and drive it. If not, you can change the rear gear.
What'd I do with my Camaro? Put in a 5-speed O/D with a 2.82 low gear. Much more pleasant to drive now.
What'd I do with my Camaro? Put in a 5-speed O/D with a 2.82 low gear. Much more pleasant to drive now.
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 2,193
Likes: 156
From: Navarre FL
Thanks for the replies. Like I said, a 5 speed would be great. But I dont think the woman will ever go for that kind of cash. $500 is doable, but much more is getting kind of steep. It would probably be more than a few years. This isnt a daily driver, so economy isnt a huge factor (although something better than 10mpg would be nice). Right now I have one source that says it should be a close ratio trans (out of a 1980 L82). This engine should make over 400lbs from 2500 on up, thats about as much as I can get and be comfortably street-able. so Im not sure there is much else that can be done there. A TKO is probably out of the question due to price. I think the way to go is to go ahead and go with this setup (close ratio with a 3.55, once I confrim the rear end gears). If it is comfortable then Ill stick with it, if not, then I can go to a higher rear end gear cheaper than going to a five speed or new tranny.
