Just picked up a 'near original' '85 Conquista that came with the original factory build sheet. This one has TONS of nice options (the main reason I went for it) including a posi rear end, a full gauge package and a number of 'little extras' such as bumber guards, bed rails, AM/FM w/cassette, power locks, and so on.

All of these and more show on the RPO build sheet, of course, but I have questions about the transmission and rear end setup.

The build sheet shows the following (amongst all the others):

E5Z LESS ADAPTER
E7Z LESS SLEEVE
E9Z LESS SPPED KY

GU2 2.73 RATIO AX
G80 POSITRACT AXL
G92 PERFORMANC AX

MV9 AUTO TRANS

V08 HD COOLING

From what I've found here, the G92 code would indicate the 3.08 gearing and yet the GU2 code two spots above indicates otherwise. Any ideas?

What transmission is the MV9? Which one of 200s is this?

What are those "LESS" codes in the E's above?

What did the V08 code option add, if anything, above the "normal" cooling?

I would be happy to list the other 40 or so codes as well if anyone is interested.

- Luke
'79 El Camino
'84 Conquista 'el partsino'
'85 Conquista "2 MUTCH"

G92 is a merchandising option code. Which means nothing about the ratio.

MV9 - TH200C

V08 - Usually is a larger capacity (1/2-1 qt more) raditor and fan/clutch

Hi Mike,

Thanks for the reply! I had searched for and found the following in another post (thread here - http://www.necoa.org/modules.php?name=Forums&file=viewtopic&t=9251&postdays=0&postorder=asc&highlight=g92&start=15&sid=c6a530c5def309c4432c876118e484bf ):

"Generally speaking, there were only four rear end ratios available for the 5th generation.

2.41 V8 standard rear
2.56 V6 standard rear
2.73 V6 optional rear (G92)
3.08 V8 optional rear (G92)

All were available with optional posi (G80).

The only exception was the 83-84 350 diesel engine Elkys. They all had a 2.29 rear.

Tranny would have been either TH200. TH250, or TH350.
_________________
Ernie
87 El Camino"

I was confused by the use of the G92 code mention after the 3.08 above. Do you know what sort of "merchandising option" this would have referred to? Some sort of signage touting the 2.73 axle? Or perhaps touting the posi rear end? Just curious...

Thanks again for the info.

You haven't mentioned what engine you have in your 85. Since you did mention that you have the GU2 2.73 ration axle, I would assume you have a V6 in your 85. If you have a V8 then the 2.73 must have been a special order.

G92 was the RPO for "Performance Ratio" in all of the 5th gen Elkys.

2.73 V6 optional rear (G92)
3.08 V8 optional rear (G92)

Hi Mike,

It has the 305 in it - and hence why I was confused by seeing both the G92 and the GU2 codes on the same sheet. I've tried and tried to read the code off the axle itself, but it's a VERY light stamping and is just not readable. Would the axle ratio be listed anywhere else on the car?

With the 305, what would have been the "standard" axle to make the 2.73 a special order (so that the G92 RPO would be needed)?

Still wondering what the "LESS" codes refer to...

Hi Mike...
No, my name is Ernie but if you want to call me Mike I guess that's OK.

...It has the 305 in it - and hence why I was confused by seeing both the G92 and the GU2 codes on the same sheet...
Well, I guess I'm confused too. A V8 Elky with a G92 RPO should have gotten a 3.08 rear. But, as I stated before, if a 2.73 was specified on the build sheet it must have been a special order.

...Would the axle ratio be listed anywhere else on the car?
No. You can always jack up the rear end, put it in neutral, and spin a rear tire to count the number of driveshaft revolutions for one wheel revolution. That will give you an approximate ratio.

...With the 305, what would have been the "standard" axle to make the 2.73 a special order (so that the G92 RPO would be needed)?

As I stated previously:

Generally speaking, there were only four rear end ratios available for the 5th generation.

2.41 V8 standard rear
2.56 V6 standard rear
2.73 V6 optional rear (G92)
3.08 V8 optional rear (G92)

A merchandising option is a sales option used by the marketing division to include specific content. Performence axle is a marketing term and generic. Wow, I got a performance axle but its only a 2.73. Many would equate a 3.73, 4.10 as a performance axle. Thus the merchandising term beign a fancy word for sales feature..

Rear axle ratio depends on many things. The trans, engine, A/C, and a host of other things all predetermined. You may want a 3.42 ratio for instance but the options force a 2.73 ratio because from an engineeing stand point, a 3.42 would not cut it with the other options. (ps-I am only using examples).

So a G92 is the code for an performance axle ratio but one the Chevy determines is applicable to that vehicle. it could be any ratio. Oldsmobile could use the same code and it mean something different on a 442. In other words, Chevy said you get a performance axle, it could be one of these two ratios that we determine is right for the truck but since we don't know what it will be, lets call it G92 performace ratio and when our assembly plant computer sees this code, it will pick the ratio we programmed in the list of applicable ratios as determined by engineering to be compatibale with the other options ordered.

I probably did not explain it well but it is hard to explain.

Another example maybe will help.

Take a new truck, it has option code 1SD. But that same code (merchandising) is also used on all other Chevy cars, They would not use the same ration on a truck as a front wheel drive car. So for each model it means differnt things. When that elky was ordered, the dealer chose from a option pkg and one of those ratios was part of that pkg but was llikely determined by option content and forced becuase of that option pkg.

Thanks Mike and Ernie! Sorry about the name mixup!

Out of ongoing curiousity, I will try the ol' "spin the wheel in nuetral" idea and see if that confirms either the 2.73 or 3.08. My Dad helped me understand these codes some as we went over the build sheet, but I would still like to know for sure. I plan to try and keep this one as close to original as possible and want to be able to sound credible when I explain the options and build sheet info to others at shows and such. You guys have helped a lot already and I will undoubtedly have more questions as I go along.

Still looking for info on those "LESS" codes. I understand it probably means that things were eliminated or removed from the 'base' (or from certain option package groups), but what things? Again more for future info purposes than anything else...
Thanks again!

This old thread may help clarify some of the "missing" RPO codes question. They are not "RPO Codes", but "build sheet" codes. The difference is sorta spelled out in this thread.

http://www.elcaminocentral.com/modules.php?name=Forums&file=viewtopic&t=1470&highlight=missing+rpo+codes