I'm trying to make a decision between a built 4L60E and 4L80E.

The positives on the 80 are obvious. But from what I can tell, a huge advantage of the 60 are the options to keep (or even improve) geometry on the stock-length torque arm.

From what I can tell, the 80 is such a tight fit to the tunnel, that it's not possible to get the front mount of the torque arm very high.

I know I can use a dedicated mount, but this isn't a drag-dedicated car so hoping to keep the stock length arm.

 

If your HP won't tear up a 60 why go with the 80? Especially with the issues that come with it. MHO.

 

4l80e is great especially in a mostly race or high horsepower application but there is a trade off with weight and space. A well build 4L60e will be reliable in most applications and be lighter and easier to fit in the trans tunnel. I've been abusing my 4l60e from RPM transmissions for many years with no issues. Keep in mind a good quality torque converter and properly sized trans cooler also help in making any transmission last.

I wouldn't let the torque arm be the deciding factor either way, there are a lot of good choices for a torque arm and mount.

 

New setup should be pushing the upper end of reliability on a 60, which is why I'm considering the 80. But leaning towards 60 for every other reason.

Do you have any examples? I know I could do a tunnel or dedicated mount, but from everything I've seen, there isn't a way to get good geometry on a stock-length arm, when the 80 takes up all of the tunnel clearance in the mount area.

 

Check out the Holley trans crossmember and torque arm mount. PA racing also makes one for a 4l80e, that looks to be factory length or close.

 

Thanks man will check that out. The PA Racing setup is the only one I've found for the 80 on a SBC, but that's the one that worries me with geometry.

Found this vid on YouTube which shows it installed - the torque arm mount actually looks a few inches lower than stock.

 

I have an 80e in my car using the Holley trans crossmember with a MWC 9". Your best bet would be to make a torque arm crossmember just behind the trans.

Something like this. The crossmember is welded to the SFC's and is bolted in the center with the front of the TA on a 5 position mount. Midwest calls this a "mid-length" TA

 

That's an interesting idea.

Were you able to get pretty good geometry on the front mount? How does it hook?

 

It hooks really good, it uses Heim joints so there's no binding at all. The bottom holes are closer to stock and the further up you go the harder it hits the tires

 

i have a similar setup to thatsupnow.
i have a Ford 9" with a 4L80E and installed a BMR Trak Pak torque arm that moves the arm off of the transmission. the Trak Pak mounts to a crossbar that i have welded between subframe connectors.
the tranny crossmember is a PA Racing unit. things are a little tight in the tunnel but it all works.
below is the best picture i have handy for your reference.

 

Thanks guys. Did you have to custom-make your dedicated crossbar, or did you buy?

 

Mine came with the entire rear end package. I believe the BMR Track Pack comes with a crossmember as well. QA1 makes a 4l80e trans crossmember and tunnel mount torque arm. Not a bad looking piece to just be able to bolt it all in with no welding needed