There is one before and one after the catalytic converter.
.043
.43L. 1000ml=1L
4L60/E l
43L of 18-k gold
Yes it will bolt right up to it.
The EGR valve on your Astrovan is on the backside of the intake manifold just under the throttle body attached by two bolts. After installing a new gasket be sure and torque the BOLTS to 17-18ft lbs or the NUTS (if yours has studs) to 15ft lbs)
The fuel lines around the filter; you will need an adapter.
There is no adjustment required, but you can clean it with a carb cleaner.
Use an exhaust made for an LT1 engine the blocks are identical it is the insides that is different. Will bolt right on.
It should be on the front of the intake manifold directly above and behind the water pump.
Don't know what year you have but some sensors are temperature sensitive and you should run a 195 degree thermostat.