Originally Posted by Danthurs
You missed a bracket right in front.
Look out. These symptoms are possibly caused by a failed intake manifold gasket--common problem in the Bonnevilles. Coolant passes through the head to intake manifold gasket to control the temperature of the intake manifold. Failed gasket may allow coolant to be sucked into a cylinder during the intake stroke. The possibility exists of a hydraulic lock; cranking the engine while a cylinder is full of coolant will cause it (at best) not to crank, and at worst it will cause serious damage.
There are service bulletins out for some years of the Bonneville for intake manifold gasket failures. I have done mine several times, and the current fix seems to be holding. I used a Victor Reinz gasket set the last time, with grey RTV at the corners of the seal at each end of the block.
The collapsed hoses, loss of coolant symptoms could be consistent with either an intake manifold gasket failure, or a head gasket failure. Take a sample of the coolant from the suspect engine to a radiator shop and have it tested for exhaust gas products. If no exhuast gas is present in the coolant, it is probably an intake manifold gasket failure. If exhaust gases present, it is probably a head gasket.
Been there done that.