97 Sierra engine/transmission swap out

[Diving Falcon]

Hi guys, new to the forum. I have some questions. I have a 97 Sierra with the 4.3 liter V6. I would like to install a new chev crate engine/ transmission combo but am slightly overwhelmed by how many options are out there. I would like to stay with a small engine just for the fuel efficiency alone but also so I wouldn't need to change the fan cowling on it if I go with a big block instead.I would like the new one to have EFI like my Vortec and A/C so a true turn key package I would like. Transmission should stay an automatic as well. So what options are out there? Price?  Warranty?

Edited September 21, 2021 by Diving Falcon

[Diving Falcon]

Hi guys, new to the forum. I have some questions. I have a 97 Sierra with the 4.3 liter V6. I would like to install a new chev crate engine/ transmission combo but am slightly overwhelmed by how many options are out there. I would like to stay with a small engine just for the fuel efficiency alone but also so I wouldn't need to change the fan cowling on it if I go with a big block instead.I would like the new one to have EFI like my Vortec and A/C so a true turn key package I would like. Transmission should stay an automatic as well. So what options are out there? Price?  Warranty?