: Anyone tried a 6L80 on a 472?

08-14-11, 09:20 AM
Just looking around if anyone has seen, heard of, thought of, tried, dreamed of, anything really of putting a 6L80 on a 472 or 500? I have a 69 deville and was jus tpondering the issue and wondering if anyone else has looked into it at all?

08-15-11, 12:05 AM
I don't know where you even find a 6L80, but it certainly will require
a computer to shift it. There would be plenty of other issues to get
everything connected. I wouldn't use anything but a big block trans
behind a 472. Bruce Roe

08-15-11, 12:17 AM
I have never heard anyone doing it... Besides those transmissions are costing a real lot , they are not rated for the torque of a 472-500 motor..They are rated at 430 lb-ft and the big caddies put out well over 500 lb ft... I would think if the car had any weight to it and you kept your foot in it you would distroy it..

08-15-11, 10:39 AM
I am trying to figure out some options. The gas milage with the 3 speed is well not the best and having a six speed would just be cool in itself. I looked at the Allison trans but they don't like input speeds above 500 rpms. Not that I take the caddy above that but I don't want to be limited by the tranny on that end. I am hoping to find one in a junkyard for a good price. I figure someone gonna totally one of the cars they come in soon. I was really hoping to find a 6l90 from a caddy since they are a little stronger.

08-21-11, 05:18 PM
You can do a Gear Vendors unit. That will give you six speeds out of your stock TH400.

09-02-11, 11:42 PM
I just can't get over the price of them. I know they are a good deal but thinking about what else I could do with the money always stops me.