duster rear glass install help...!

i am in the process of trying to install the rear glass on my 72 duster...I have a decent backglass from a 74(are they the same)I will be reusing the old gasket..although its a little stiff it is still pretty pliable..It seems a little tight..with the glass in the channel..I do have some spray silicone and some window "sticks" to aid in the install..can anyone offer me any tips to help the install go a little easier? any suggestions warmly welcomed..:read2: