Thoughts on 700R4 to 6L80-E Swap

[Alteca]

I have driven some 6l80 and 8l90 vehicles and can confirm I love having the extra gears. A 6l80 and a 3.42 pulls off the line harder than a 4l80 and 4.10 would but the extra overdrive gear gives u that good highway mileage. Now I will also say I’m not sure that it’s worth spending a few thousand on. If u can somehow DIY it and do it for under $2k then maybe.

 

[DixieWASP]

You beat me to it. @L31MaxExpress is also doing this swap, but is converting his 350 to 58x which is the better way to go about it, though it is not for the faint of heart. I'd love to swap one, but find it difficult to open my wallet for it. The gear spread is the real advantage as Erik pointed out, you can run a taller gear without losing off the line punch. In fact you can gain on both ends. I think OD is about 150 RPM difference gear for gear.

Pardon my ignorance but what is a 58x?

 

[DixieWASP]

I have driven some 6l80 and 8l90 vehicles and can confirm I love having the extra gears. A 6l80 and a 3.42 pulls off the line harder than a 4l80 and 4.10 would but the extra overdrive gear gives u that good highway mileage. Now I will also say I’m not sure that it’s worth spending a few thousand on. If u can somehow DIY it and do it for under $2k then maybe.

I took early retirement and I am taking automobile technology classes at the local community college. I have access to a large number of tools and a knowledgeable instructor that has rebuilt many automatic and manual transmissions. With that said, I can do the swap for the price of parts and a used transmission. This makes it practical because I would not be able to pay someone to do the swap for me. Alteca, where in Alabama do you live? I am in NW AL.

 

[Alteca]

Alteca, where in Alabama do you live? I am in NW AL.

I’m just south of birmingham

 

[Alteca]

Pardon my ignorance but what is a 58x?

58x refers to the 58 tooth reluctor wheel commonly used on gen IV ls and I believe the gen V motors as well

 

[DixieWASP]

58x refers to the 58 tooth reluctor wheel commonly used on gen IV ls and I believe the gen V motors as well

Thanks for telling me. It is nice to see another Alabama GMT400 person on the forum.

 

[618 Syndicate]

I have driven some 6l80 and 8l90 vehicles and can confirm I love having the extra gears. A 6l80 and a 3.42 pulls off the line harder than a 4l80 and 4.10 would but the extra overdrive gear gives u that good highway mileage. Now I will also say I’m not sure that it’s worth spending a few thousand on. If u can somehow DIY it and do it for under $2k then maybe.

Agreed completely, it's about money.
I doubt one could even get hold of a 6L for under $2k, but if a guy could find one cheap it'd be cool.

 

[L31MaxExpress]

Agreed completely, it's about money.
I doubt one could even get hold of a 6L for under $2k, but if a guy could find one cheap it'd be cool.

I found a 6L90E with 47K miles for $1500 shipped to my door without a core charge.

 

[Supercharged111]

I found a 6L90E with 47K miles for $1500 shipped to my door without a core charge.

See, that's what I thought they went for myself.

 

[618 Syndicate]

A used trans is a gamble, and a rebuild kit is about $500, so right at $2k if you rebuild it yourself, or have access to someone like the op.
And you still gotta find a way to control it.