Mini-Van or Maxi-Van?
Hardly. These vans are often misunderstood. They are like a wolf in sheeps clothing. GMs Astro/Safari vans make great tow rigs for pulling your "Rock Buggy" to the trails. They have enough room to haul all your extra tools and gear as well as a strong engine and drivetrain. They can make a great place to sleep on those extended trips especially when the weather is bad. When outfitted properly they also become good for moderate off road use. No kidding. We have had several outfitted vans over the last decade or so and know what these vans are capable of. Check out some of the pictures below and you will see what we are talking about. Contractors, surveyors, fisherman, bike racers, snowboarders, kayakers, hunters and nature photographers, just to name a few, have used these kits to "boldly go where no van has gone before".
General Information
Introduced simultaneously by General Motors in 1985 as a Chevrolet Astro and a GMC Safari these two vans stood out from the crowd. Smaller, more agile and more fuel efficient than the full size vans of the day yet able to handle a large payload and tow heavy trailers. These were not car platform based mini-vans but were built like a truck. In fact many of the drivetrain parts are shared with their pick-up truck cousins.
In the early Astro/Safari vans a 2.5 inline four gas engine was standard that only had 95 HP and 134 pounds of torque. This 4 cylinder was considered underpowered by most and eventually phased out. A 4.3 V6 has been the primary power plant through the years. Some early models had a carburetor but that too was left behind in favor of the TBI fuel injection system. This engine produced a healthy 165 HP and moved these mid sized vans along nicely. With the introduction of AWD in 1991 the 4.3 was fed through a multi port fuel injection system. This raised the out to 210 HP. The latest Vortec 4.3 V6 has 190 HP and 250 pounds of torque. It was introduced in 1995 and proved have a more usable powerband although the overall horsepower was less.
Some early models actually had a manual transmission but like the 4 cylinder motors they became extinct. the automatic transmission is one that has performed well in these vans. It is the TH700 R4 otherwise known as a 4L60. In the mid nineties Gm added an electronic control to these transmissions and the became known as 4L60E.
With the optional addition of a Borg-Warner 4472 transfer case and a 7.2" (same as S-10) front differential in 1990 these vans became AWD and could get to places other vans never could. In 2000 an electronic controlled transfer case replaced the 4472. One advantage to this is that a switch can be wired into a sensor on the transfer case allowing the owner 2wd operation when desired.
The typical differential gear ratios for these vans are 3.42 or 3.73:1 ratios. However gears changes of 4.10 and 4.56:1 are available. The rear differential is a 7.5" (7.625) and is housed in a GM 10 bolt axle. A factory locking differential (G80) was available as are several aftermarket lockers for both the front and rear differential.
The factory equipped these vans with small tires for their size. A P205/75R15 is only 27" tall and 8" wide. Unfortunately this also means that GM designed the wheel openings for smaller tires. In order to effectively use larger tires a lift becomes necessary. By installing a 2" lift you can run 235/75R15 tires. A 4" lift makes room for 31" tires. We have found a 30x9.50 and 31x10.50 to be excellent tire sizes for these vans for most applications.
Very few companies offer products to outfit these vans for the rigors of off-road use. We are proud to be one of them.
