Hey guys got a tranny question here,Will a 4l80e fit in my 1999 Chevy Tahoe its 2wd as is the tranny but i have the 4l60e? Do I need to get any extra parts/peices or will she just bolt up in place of the old one? The guys is selling two of them one thats 2wd and another thats 4wd i dont know anything bout 4wd just that its heavier duty.Also if i add the 4l80e does my ECM need to be reflashed/reprogrammed? Let me know people so i can swoop on one before its gone he is selling both of them for $275 each they look clean in the pictures and he is selling them with rebuilt internals need to know ASAP!!