1977 C20 4L80E swap

[lcfman]

I am considering a 4L80E swap in my 77 C20 with 454. My question will the trans fit without any body modification to the transmission/firewall area? Any other helpful comments welcome. thanks

 

[Vbb199]

@Catbox

 

[lcfman]

???

 

[Catbox]

He has tagged me as I am planning to swap a 4L80 into my truck as well.
Mine is a manual SM465 truck, so I have a bolt in tunnel cover on my floor.

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You do not mention if you are an auto or manual already.

I do not think that I will have any issues with the transmission case size in my truck.
I cannot verify if an auto will be the same.
I would not think there would be any issues though.

 

[Craig 85]

I've never priced it out a 4L80 swap, but if you haven't looked at a Gear Venders OD, here's some pricing and info.

https://www.gearvendors.com/hrgm3s.html

 

[CheemsK1500]

For a 4L80E to go behind a 454 and actually shift, you'll need to either do a manual valve body conversion (This effectively turns your automatic transmission into a full time semi-automatic transmission) or you can install a stand-alone shift module and retrofit a throttle position sensor to your carburetor to retain automatic shifting.