The intake valve is bigger.
in the back of the intake maniford on the passenger side
yes
yes
The intakes are always bigger than the exhausts.
Yes they are the same.
intake manifold is DIFFERENT for models 1985 and 1988
Yes, I just changed a 1985 305CI intake to a new GM 350CI long block crate motor.
yes
If the ports on the heads on the 88 are the same as your 76 intake it should work.
G.M's 305 cubic inch V8 motor is a 5 liter
1996 chevy c1500 pick up 305 motor bolt torque spec intake manifold