Using an Astro/Safari MiniVan 4.3

I just completed swapping the engine from a 1992 GMC Safari van into my 89 S-10 Blazer. Here are some of the differences I encountered.

The oil pressure sender is on the opposite side of the engine and had a different connector than mine. While trying to remove mine it got destroyed. My solution was to find another van in the local junkyard and peel back enough of it’s harness to get the connector and three feet of wire. I then spliced this into my trucks harness. The readings seem accurate. The plug used to seal the hole where a sender is not in both engines baffled me. It has a square indentation that is not, I repeat, NOT either a ¼ or 3/8 inch drive.

Exhaust manifolds were completely different. The problem this causes is that the heat stove (sheet metal piece wrapped around the manifold to route heat to the air intake) on the Blazer manifold wants to be right where the sender mentioned above sits. Being sheet metal, the short term fix for this is to just bend the stove out of the way.

The van engine has a front sump oil pan (meaning that the deep part of the pan sits towards the front of the engine. The Blazer is a rear sump. This has to be swapped out, not forgetting to swap the oil pickup, which just twists out of the pump. Some minor differences in the location of bolts/studs for locating tranny cooler brackets.

The coolant outlet in the rear of the intake manifold for the van does not match. I could find no threads on it. The Blazers had to be swapped in. After removing, the broken remnants of the vans were ez-outed.

The vans intake had a plug where the vacuum line for the brake booster hooks up. Easy fix there.

The vans knock sensor was attached to the block with a brass adapter that had a different angle than mine.

The vans water pump had a 5/8 inch outlet the Blazers did not. Rather than swap water pumps I just sealed it off with a short length of heater hose with a broken off wheel stud that I had lying around.

The valve covers rubber grommets had to be swapped around to match the PVC/other thing routing. Also the long neck filler tube of the Blazer will not thread into the van covers. I’m not above using a funnel til the next engine change. I just removed the whole map sensor assy (tall bracket between the TBI and the passenger side valve cover, none of the connectors matched or the vac lines.

Writeup by Bill Kitchens

Last Modified: 7-13-05 JCH