Two (2) Seat Springs Fits Oliver Tractor Models 66 77 88 Artofit. Two (2) Brand New Aftermarket Replacement Rubber Seat Springs Fits Oliver Models: 66 (Industrial sn 462051 462255), 66 (Rowcrop sn 420151 429770), 66 (Standard sn 470406 474231), 70 (When Updated To Late Style Seat W Rubber Torsion Springs), 77 (Industrial sn 403186 403290), 77 (Rowcrop sn 325601 347731), 77 (Standard sn 270566 273375), 88 (Industrial sn 920506 920855), 88 (Rowcrop sn 124704 136898), 88 (Standard sn 821962 826415), [90, 99 (sn 516841 and up)] Tech Info: List is the serial numbers based on the factory installed seat. However, your seat may have been switched out from a different serial number tractor over the years. We recommend reviewing and comparing the picture in addition to the serial number to ensure that the correct product is ordered. Does not include bush