Oh
god I hate those spider injection vortec engines. Absolute garbage. The v8s aren't
that bad, but the v6s are not even worth the time or money, imo. If anyone here has one of those, just... do yourself a favor and get rid of it.
If you're doing a lower intake gasket (very common to leak coolant, btw), while you're at it, replace that spider crap with the retrofit kits you can buy. They're literally the same price as the oem type spider, it's direct fit, looks similar, but instead of the stupid poppet valves that require surgical cleanliness and precise amounts of vacuum to operate (which you're not going to get from an engine designed in the 1960s) it uses mini regular injectors.
->HERE<-
Also, when you're reinstalling the upper intake, be extremely careful with the giant oval-shaped o-ring around the big ol' injector plug - it's VERY easy to pinch. Rub it with grease - a little, not a lot - and
ease the intake down onto it, focusing on that seal, and take your time.
Also, also, the distributors on these always have problems. They get loosey-goosey sometimes and the shaft wobbles inside. And despite being non-adjustable, they actually have some wiggle room, and need to be adjusted to 0 degrees +/- 1 degree. Kind of need a scanner for that, unfortunately. You also have to do it pretty much while the engine is hot and running, it's very unpleasant, but should be much easier on a van than on a pickup. After you finish the intake, you'll probably get a check engine light for crankshaft/camshaft correlation, because of the distributor adjustment.