This is what it shows in my parts book:
OEM #90506-20281-00
For Gas and Electric G1(1982-up)
G2,G8,G9 up to 1992
3-1/4" Brake shoe return spring used for either upper or lower.
But, it also shows this:
OEM #90506-26191-00
For Gas and Electric G1,G2,G8,G9 up to 1992
3-3/4" brake shoe return spring used as both upper and lower.
One is 3-1/4" and the other is 3-3/4". The wording in the book doesnt really make sense but mabye this will help.