Take all the oil out then unscrew all the bolts and take a scraper razor blade where the gasket sits between the engine and the pan clean the pan and then put the gasket in place put the bolts back in and torque them to what it says make sure not to tighten them to much don't want to strip any of the bolts
remove the intake hose and the exhaust port screwed into the egr valve, the remove the two retaining bolts from the intake and clean any old gasket material away. if possible run a piece of wire down the hole to make certain the passage is clear of carbon build up
Use an exhaust made for an LT1 engine the blocks are identical it is the insides that is different. Will bolt right on.
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)
There is one before and one after the catalytic converter.
The fuel lines around the filter; you will need an adapter.
Several possabilities. One is a bad PCV valve if it leads to that bank of cyl. Another is the intake gasket for that side of the engine. Worst case, but not likely as it is affecting all of the cyl, is a failed head gasket. One question, are the plugs fouling with fuel or oil? If over fueling, it could also be an injector or injector wireing issue. Could it also be bad oxygen sensors? If there are four oxygen sensors on this van, and the one for the right bank of cylinders is giving the wrong reading, that could cause this problem. Seems unlikely, though.
There is no adjustment required, but you can clean it with a carb cleaner.