Tall Rear End Gears

[Piotrsko]

Ok im at a loss here.... except for the expense, there are blank 3rd member kits offered for just about anything ever manufactured and probably ratios as well. I have even seen quick change diffs as a kit. Worse case is buying and welding the correct brackets.

[racprops]

My 93 Chevy Van is a special case, it turns out it has the widest rear end in such a van, even the second widest rear end out or a 70 GM Largest station wagons is about 2to 3 inches short. And the newer 96 van rear ends are shorter.

Plus they have not made gears in the 2:0 to 2:5 ratios sense the 70s for GM rear ends, nor the carriers for those gears. To get the rear end in the 2.24 or even 2.43 the only way was to find a 40 to 50year old wagon rear end. AND to get a possi same thing…and then to find a rebuilding kit for that possi even harder.

The estimated cost IF I can find such a rear end is in the range of $1000.00 to $2000.00 to rebuild it and then to modified the spring mounts.

AS I have held onto two of the old 3speed w/od transmissions, my only costs will be to have a coupler to connect the output shaft of the 4L60 to the input shaft of the OD, a special new drive shaft, and to rig up a VSS sensor system so the truck reads it speed from the back end of the OD unit. I figure the cost to mount the OD is around $400.00 to $700.00.

This will give me a full 5 speed. And IF I can find the use of the gear splitting of a second OD I get 8 forward gears. I only consider that a help when claiming long hills by being able to select the best gear for load, power and RPMS.

[hat_man]

Forgive me if this has already been mentioned.

**Disclaimer** I am not very mechanically inclined and maybe this isn't a possibility anyhow.

I saw in an earlier post that the G20 was offered with a 2.41 and the Astro may have been offered with both a 2.29 and 2.14 although possibly offset. If the axle shafts are the same diameter between the G20 and the Astro could you have a custom rear made using the shafts from your van and the "pumpkin from an Astro? It would give the taller gearing you want and the dimensions/spacing/etc of the stock set-up. Again I'm not all that mechanical so I have no clue how this may affect the driveshaft arrangement or the load capacity.

I don't know much about the GM transmissions (and it may have been mentioned before) but why the automatic? A manual would be lighter and give you control over the gearing and shift points. I have always had better mileage with a manual trans as opposed to an automatic. It would also give you the opportunity to coast at idle rpms in neutral (not good for the automatic) and with a heavy flywheel it would probably coast farther than with a stock weighted one if left in gear. A Tremec TR-6070 could get you all the way down to a 0.45 top gear and save about 100 lbs.

[racprops]

Please recheck that post for a G20 with a 2:41, I think you read a 3:41 or 43 which is what my Van's rear end is.

I believe the Astro uses a smaller lighter rear end, even the G20 rear end is nearlt too light.

As for a automatic I used to drive cross country to conventions and would run into cities at bad times and working clutch though such is too painful for me to do.

Also there are a few advantages to a auto.

Rich