You won't believe the reason for having to take this manifold off....to replace a $10 hose. Poor engineering at its best. Later engines have 2 steel lines that are accessible from underneath.
I have an increasingly bad coolant leak at this hose that runs from rear of the block to the oil filter housing. It is a small 1" diameter hose shaped like a "V". The other line is a steel line from the water pump to the oil filter and has two "o" rings that sometimes leak. There is no access from below. The hose is directly beneath the second (from firewall) intake pipe. You could conceiveably get the hose clamp off at the block end but the clamp at the oil filter is impossible to get to.
Thanks for your help,