The brake shoes, front & rear ARE the same for 1966 & 1968....
1965 - 1968 Pontiac --- 5 lug & 8 lug drums are:
Fronts:. 11" x 2 3/4" --- the old # 260 brake shoe.
Rears: 11" x 2" --- the old # 272 brake shoe.
From 1959 - 1964 , the Fronts were 11" x 2 1/2" &
the Rears were 11" x 2" --- but a very different shoe....
On 8 lug brake drums, ESPECIALLY, don't dare use any new fangled garbage friction material ---- you will rip those drums to smithereens...
It is +++ critical +++ to use N.O.S. ++ Asbestos ++ brake shoes --- the softest, smoooooothest braking surface known to mankind...
That is where I come in --- I have N.O.S. Asbestos Brake Shoes....
Always best to simply call me --- Craig --- 516 - 485 - 1935.....