How to spot the towing package or posi

I'm on the lookout for a good wagon and one thing I'm thinking would be nice is the towing package. What's the best way to spot them? Is there a way of telling by looking at the fans? (mechanical+electrical=towing?)
I know there are codes somewhere that can be used to identify them.
I'm also interested in the posi option. What codes are associated with them and do they have any relation to the towing package?

On a stock 94 to 96, 1 mechanical and 1 electric fan = towing package, which includes posi rearend (2.93). The non towing has 2 electric fans and non posi rearend (2.56).

Tom

The presence of a mechanical fan on an LT! car is a dead giveaway for the tow package. On a TBI car "trailer provisions" is V92 on the SPID. The V92 may also be on the LT1 SPID.

If you look at the SPID on the passenger's side D pillar, the posi will be noted as "G80" If the SPID is faded to the point where you can not read it, the posi rear will have a tag on one of the cover bolts.

Thanks, I'll look out for the G80.

Does the presence of the mechanical fan make working on the car much harder? I'm not planning on towing much other than a utility trailer but the wiring harness is a big attraction.

There is no wiring harness with the tow package. Tow package is nothing more than heavy duty cooling and a posi rear.

Ok.

Look at the Service Parts IDentification (SPID) sticker inside the right area tailgate opening and look for:
V92 = towing prep package
GU4 = 2.93 rear axle
G80 = posi (this was optional, and some V92/GU4 cars didn't get it)

GW9 = stock 2.56 rear axle. Some cars are dogs with this ratio and some cars drive just fine.

Superior Finish wrote:

Tow package is nothing more than heavy duty cooling and a posi rear.

There's more to it than that, based on cross referencing parts. It is worth getting a tow package car unless you find a super clean non-towpack car. The good news is that most Roadmaster Wagons did come with the tow package.

No, the mechanical fan setup does not make these cars much harder to work on. You won't be doing much work to the front end of the motor outside of water pump and distributor replacement which are not often, and undoing the mechanical fan adds maybe 10-20 minutes of work.

I had a mechanical fan setup for 8 years and it never bothered me. You do get much better continuous cooling in the summer with this fan (it's huge), and in the winter I just left the fan belt off. You can get the main serpentine belt and the mechanical fan belt off the car with the fan in place so that's no issue, and since you're studying auto tech you know that belt materials have changed now to where they never just break; they only wear, so your chances of being on the side of the road with a broken belt are negligible.

Some of these cars have had the mechanical fan deleted and replaced with electric fans. The wiring harness for the dual electric fans is completely different from the mechanical fan / electric fan setup so it's very difficult to do it "factory style" with the proper wire colors, connectors, etc. (I did the conversion on a car last summer and I had way too much time into it). There is an aftermarket harness available to do it which is well constructed. If the car has been converted, be sure to check to see that the wiring was done well and placed well. There are also three different fan motors used in these cars; if the previous owner converted to dual electric fans, ask him which wattage motors he used and make sure he used the correct ones.

Tow package doesn't always mean posi rear. at least not for 91-93. It will have heavy duty cooling and heavy duty suspension, with rear air shocks (buick only I think, not sure on Chevrolet). I thought we had a thread on this posi thing from a couple years ago. I can't find it but I'm still looking.

sherlock9c1 wrote:

Look at the Service Parts IDentification (SPID) sticker inside the right area tailgate opening and look for:
V92 = towing prep package
GU4 = 2.93 rear axle
G80 = posi (this was optional, and some V92/GU4 cars didn't get it)

GW9 = stock 2.56 rear axle.   Some cars are dogs with this ratio and some cars drive just fine.  

and since you're studying auto tech you know that belt materials have changed now to where they never just break; they only wear, so your chances of being on the side of the road with a broken belt are negligible.

Thanks for the codes,
And while all my research is for GM, I'm not in Auto Tech. I'm in mechanical Engineering studying materials to be used for body and chassis. So yeah, I do know the belts have changed, but don't think I'm an auto expert. Most of my hands on knowledge has come from my own cars and forums like these.

This thread discusses the towing package and Sprocket even mentions on the first page that the (G80) posi was optional on tow pack cars. I can verify that my 1993 RMW has the towing package option, without a posi (LSD) rear end. (3.23 open differential)

Thanks

j2rossit wrote:

 I'm in mechanical Engineering studying materials to be used for body and chassis.

Good for you. The world needs more folks like this.

Thanks, I plan on graduating in the next few months at which point I will most likely end up in GM Canada (still working out the details).

Don't know about the 92s and 93s but the 91 tow pack cars have a boxed frame under the rocker panels while the non tow pack cars are open channel. The later cars all seem to use channel regardless of option pack.

Bill

My 92 RMW was boxed, non tow pack.

As others have pointed out, G80 was optional on tow pack cars (but common). My (dead) 94 has it.