Yes it will.
YES it will.
No it will not it is all different, It won't even match up with the cab.
NO it will not work. Everything is different. Cab mounts, body weith, ECt.
Yes, There the same.
Yes, It will bolt right up.
Unbolt it from the floor.
it is made of aluminum alloy
No they are not, The 78 does not have a computor. But the 88 does have and that means more wires and different wires.
High-powered explosives.
SAE 10w30
117.5 longbed is 131.5
Look in your owner's manual and under the hood on a placard and you will find the answer to this question.