Overdrive on a 727?
- Thread starter Andy
- Start date
Russ69Runner
Well-Known Member
With my four-speed car look for another gear due to my other vehicles all have it. Passion sells an overdrive four speed transmission. They are way out on the time to get one have to get in line. Gear vendor is another option costly also. Have read you need to put another cross member in to Carrie the unit. It would be nice to have over drive but guess I will just live with what I have. Some of the other guys might have better info that have changed up to an over drive unit.
Rapid Transit
Just A Traveler In Time
If you don't plan a racing anyone, my option would be changing the rear gears.
Especially with the torque multiplication of an automatic transmission.
Or better yet get a spare center section with different gears.
I would think that's the cheapest and simplest option if it fits your needs and assuming you probably have a 3.23 or better.
In realty most driving is just tooling down the open road anyway.
What I did was go to a 2.76 center and had Brewer build me another 833 with a low ratio first gear.
http://www.brewersperformance.com/products.php?cat=126
https://www.doctordiff.com/8-3-4-helical-gear-sure-grip-sure-trac.html
Especially with the torque multiplication of an automatic transmission.
Or better yet get a spare center section with different gears.
I would think that's the cheapest and simplest option if it fits your needs and assuming you probably have a 3.23 or better.
In realty most driving is just tooling down the open road anyway.
What I did was go to a 2.76 center and had Brewer build me another 833 with a low ratio first gear.
http://www.brewersperformance.com/products.php?cat=126
https://www.doctordiff.com/8-3-4-helical-gear-sure-grip-sure-trac.html
Last edited:
41dodge
Member
I used to swap my 3rd member, w/ 4.10 ratio gears w/ Detroit locker every Wednesday afternoon so I could go bracket racing Wednesday night racing at O.C.I.R. I'd baby it to work on Thursday and Friday, then go street racing on Friday nights, then back to O.C.I.R. or Lions on Saturday and Sunday I'd change back the pumpkin to my 3.23 posi gear-set one on Sunday night to get it ready for work on Monday. I got to where I could swap out my center section in under an hour. There's also the option of using an A-518 with the O.D. as that is what I'm putting behind my built 440 in my 69 Roadrunner I'm building.
Danomt
Well-Known Member
Where do you find a 518 that will bolt up to a big block....?
41dodge
Member
There are a couple if sites that sell fairly simple adaptor kits, just for that swap. I'll have to go out and look through my boxes and see who made this one. At the time I purchased mine, they were the only ones making this kit which included the linkage and solenoid switches to activate the overdrive and torque converter lock (if so equipped.) Just do a web search for A-518 to Big Block adapter and see what pops up. I found https://www.coperacingtrans.com/?product=small-block-to-big-block-adapter-6-bolt-crank, and https://transmissioncenter.net/shop...ge-small-block-518-transmission-6-bolt-crank/ Maybe you can find more or someone selling one. I was just shocked to see that they are going for now compared to when I purchased mine and then it came with what are now options. I just need to get well and healed up enough to go back to work on my 69 RR.