my 90 big block suburban had a 400 in it . I too did not think that a 4L80E was even on the planet in 1989 ????? 700r4 yes ,,,, but not a 4L80 on a Gen II motor. but i have been wrong a couple times in my life .
Forget it ... I just reread the post .... I'm the idiot now !!!
The 4L80 E is just a beefed up 4L60E , same case , same valve body just much stronger guts. GM runs them behind the 6.0 and 8.1 gas motors . Mommas Denali has the 80 in it .