Did you just line both of them up together and see length checkers etc.? I never did and just used my old one out of the 4L60. Never had one out of the 80 to check with. Would figure they are the same. Or close. I just put the right amount of QTS in it and ran it. It came up correct on stick. Figures it was alright and that's been 1-1/2 yrs

 

When I had both tubes out, my stock 2006 60e dipstick when fully in and locked stuck out of both the 60e and 80e tube the same amount. It should work fine, but like said earlier, the 60e dipstick does seem to be tad lose at times when locked down but seals just fine.