Rebuilding a 1972 Plymouth satellite on a budget

[AdamBrooks98]

You should ask them for the environmental study to show how many emissions the police car and tow truck contributed, and how much cleaner will the world be now that they have your $170.

I consider myself lucky that they didn't lock it up in area 51 or something, things here tend to get worse the more questions you ask. At least I have the car back and I can check the rear gear numbers tomorrow morning

 

[Mopar Hunter]

 

[Kern Dog]

Most the 72 318 cars have 2.73 in a 8.25 rear. That is already highway geared, ready for a road trip. Simple to check and see what you have.

There was no 2.73 gear ever offered in a classic Mopar. The 8 1/4" axle got a 2.71 though. That seems to be a common ratio. I've had 2 '70 Chargers with that axle and that ratio.

Your car likely came with a 8-1/4, but could still have an 8-3/4. The 8-1/4 could go as low as 2.45. For the 8-3/4 the lowest numerical ratio is 2.76. The difference in revs on the highway from say a 3.23 gear is pretty significant.

This is true, though the 2.45 ratio wasn't too common until 1974. For some reason, the 8 1/4" axle had some oddball ratios.

Used extensively in passenger cars beginning in 1969, the 8 1/4-inch housing also was used in 1971 and newer Dodge B-vans and pickups. This differential is a great candidate for upgrading many Mopar 7 1/4-inch rear ends by adding strength without spending a lot of money. Original passenger car ratios ranged from 2.45:1 to 3.21:1. The truck 8 1/4-inch differentials had additional ratios of 3.55:1 and 3.90:1. A fuel-sipping 2.24:1 ratio was offered in some 1980-'89 passenger car applications, too. Aftermarket suppliers even offer 4.10:1 and 4.56:1 ratios, bigger than original equipment.

 

[Curiousyellow71]

There was no 2.73 gear ever offered in a classic Mopar. The 8 1/4" axle got a 2.71 though. That seems to be a common ratio. I've had 2 '70 Chargers with that axle and that ratio.

This is true, though the 2.45 ratio wasn't too common until 1974. For some reason, the 8 1/4" axle had some oddball ratios.

Used extensively in passenger cars beginning in 1969, the 8 1/4-inch housing also was used in 1971 and newer Dodge B-vans and pickups. This differential is a great candidate for upgrading many Mopar 7 1/4-inch rear ends by adding strength without spending a lot of money. Original passenger car ratios ranged from 2.45:1 to 3.21:1. The truck 8 1/4-inch differentials had additional ratios of 3.55:1 and 3.90:1. A fuel-sipping 2.24:1 ratio was offered in some 1980-'89 passenger car applications, too. Aftermarket suppliers even offer 4.10:1 and 4.56:1 ratios, bigger than original equipment.

Correct. 2.73 is a gm ratio. I will edit my post.
8.25 isn't a bad rear end. With a sure grip it can handle decent power on the street, even a bb. Weak spot seems to be the spider gears in a open rear end.
8 1/4 is a c clip rear with axle bearings that use the axle itself as the inner race like 8.8 Fords. Likely a much cheaper rear end to make then the 8 3/4.
Our 72 satellite has a 8 3/4 out of a 69 polara. We also used the larger drum brakes, and added a rear sway bar off a 78 magnum.

 

[peabodyracin]

First, thank you for your service! Second, welcome to the forum.

In 1973 I got discharged. I changed out the rear end gears, bolted a trailer hitch to this car, hooked a 33 Chevy street rod behind it, packed my belongings in it and drove from San Francisco to St Paul, Mn. What a trip that was, but I made it and still have the wagon. In fact the engine in it is pretty much the same one that got me home back then. Gas mileage was not the best! Dropping the 4 speed without a jack on the side of the interstate in Nebraska to change the throw out bearing was probably the most memorable day of the trip.

Best wishes with your preparations and safe travels.

 

[ckessel]

On my trips to Vegas, I would go through Palm Desert to the 10w, go up through Yucca Valley, then 29, then head to Amboy, get on the old 66 for a few miles, then get on Kelbaker road, go to the bustling village of Kelso[ way cool old train station there thats been restored] then head to just above state line. Neat, stress free drive.

 

[AdamBrooks98]

View attachment 1592690

Thanks!

 

[AdamBrooks98]

There was no 2.73 gear ever offered in a classic Mopar. The 8 1/4" axle got a 2.71 though. That seems to be a common ratio. I've had 2 '70 Chargers with that axle and that ratio.

This is true, though the 2.45 ratio wasn't too common until 1974. For some reason, the 8 1/4" axle had some oddball ratios.

Used extensively in passenger cars beginning in 1969, the 8 1/4-inch housing also was used in 1971 and newer Dodge B-vans and pickups. This differential is a great candidate for upgrading many Mopar 7 1/4-inch rear ends by adding strength without spending a lot of money. Original passenger car ratios ranged from 2.45:1 to 3.21:1. The truck 8 1/4-inch differentials had additional ratios of 3.55:1 and 3.90:1. A fuel-sipping 2.24:1 ratio was offered in some 1980-'89 passenger car applications, too. Aftermarket suppliers even offer 4.10:1 and 4.56:1 ratios, bigger than original equipment.

How would I check to see what my axle size is? Would the vin have that information?

 

[AdamBrooks98]

First, thank you for your service! Second, welcome to the forum.

In 1973 I got discharged. I changed out the rear end gears, bolted a trailer hitch to this car, hooked a 33 Chevy street rod behind it, packed my belongings in it and drove from San Francisco to St Paul, Mn. What a trip that was, but I made it and still have the wagon. In fact the engine in it is pretty much the same one that got me home back then. Gas mileage was not the best! Dropping the 4 speed without a jack on the side of the interstate in Nebraska to change the throw out bearing was probably the most memorable day of the trip.

Best wishes with your preparations and safe travels.

View attachment 1592750

That's the kind of story I'm hoping to come away from this with. I'm sure I'll have my own set of misadventures along the way, it's been awesome hearing about what other guys have done before and how it went for them

 

[AdamBrooks98]

On my trips to Vegas, I would go through Palm Desert to the 10w, go up through Yucca Valley, then 29, then head to Amboy, get on the old 66 for a few miles, then get on Kelbaker road, go to the bustling village of Kelso[ way cool old train station there thats been restored] then head to just above state line. Neat, stress free drive.

That's the exact same route I take, only I start in 29. Did you ever stop for gas at Roy's?

 

[ckessel]

Was Roy's that old station in Amboy? The times I went through, it and the hotel etc were non op. Cool looking place from the 50's/60's. Great for photo shoots. I know they filmed some stuff there for the back drop. If you haven't done it yet, check out that train station in Kelso, if it's open. Neat history there, especially WW2 era.

 

[AdamBrooks98]

Was Roy's that old station in Amboy? The times I went through, it and the hotel etc were non op. Cool looking place from the 50's/60's. Great for photo shoots. I know they filmed some stuff there for the back drop. If you haven't done it yet, check out that train station in Kelso, if it's open. Neat history there, especially WW2 era.

Yessir, the gas station is rough but it is operational now. I'll definitely check out the train station in Kelso the next time I'm headed to Vegas

 

[Kern Dog]

How would I check to see what my axle size is? Would the vin have that information?

Old cars didn't have the equipment breakdown as easily accessible as newer cars do.
Documentation only tells you what the original build was. Previous owners may have changed things in the 50 years the car has been on the road.
Originally, there was some type of metal tag attached to the differential cover with the ratio listed on it. If the cover has ever been removed, there is a chance that the tag was lost and not reattached.
You can also remove the differential cover and spin the rear wheels to get the ring gear to rotate. They have a series of numbers in them, the ratio is one of them. Chances are very likely that it is a 2.71 since that was the most common. Pre 1971 Performance oriented cars came with deeper gears with higher numbers like 3.23 and 3.55 but by 1972, reduced emissions and economy were becoming the new trend so the axle ratios started to be scaled back. Not many 1972 and later cars got the aggressive deep axle ratios unless the car had a "towing package". That option was listed on the build sheet. The build sheet was a piece of paper that was essentially a recipe for the options on each car....they were printed prior to assembly for the assembly line workers to read so they could pick the correct parts during assembly. Sometimes they were left in the cars as they went down the line. People have reported them under the carpet, wedged in the seat cushions, above the glove box and other places. They were "trash" back then and an easy way to get rid of them was to just stuff them in the cars as assembly was finished.

 

[AdamBrooks98]

Old cars didn't have the equipment breakdown as easily accessible as newer cars do.
Documentation only tells you what the original build was. Previous owners may have changed things in the 50 years the car has been on the road.
Originally, there was some type of metal tag attached to the differential cover with the ratio listed on it. If the cover has ever been removed, there is a chance that the tag was lost and not reattached.
You can also remove the differential cover and spin the rear wheels to get the ring gear to rotate. They have a series of numbers in them, the ratio is one of them. Chances are very likely that it is a 2.71 since that was the most common. Pre 1971 Performance oriented cars came with deeper gears with higher numbers like 3.23 and 3.55 but by 1972, reduced emissions and economy were becoming the new trend so the axle ratios started to be scaled back. Not many 1972 and later cars got the aggressive deep axle ratios unless the car had a "towing package". That option was listed on the build sheet. The build sheet was a piece of paper that was essentially a recipe for the options on each car....they were printed prior to assembly for the assembly line workers to read so they could pick the correct parts during assembly. Sometimes they were left in the cars as they went down the line. People have reported them under the carpet, wedged in the seat cushions, above the glove box and other places. They were "trash" back then and an easy way to get rid of them was to just stuff them in the cars as assembly was finished.

I know there's still a tag on the diff, I recall seeing it when I exchanged the fluid a few years ago. I have to teach some classes this morning and afternoon, but as soon as I'm done with that I'll head back out and check that diff tag. I also called around to a few shops in the area and got some quotes on machining and balancing in case I decide to pull the engine before I leave, I've heard everything from $1500 to $3500 to have the machine work done. I know I'm in California but does that sound a bit expensive just for machining?

 

[Kern Dog]

Maybe I've been in a cocoon for awhile but I paid $800 the last time I went through a whole big block. For that, the man bored and honed the block, went through the heads, ran the stuff through their hot tank for cleaning and swapped the pistons on the rods. I assembled it. $800. In 2022 I went through my 440/495. Again, I had it bored and honed, the decks surfaced and cleaned. I hung the pistons myself. The heads were just cleaned and surfaced. Same $800. It seemed cheap so I tipped the man $100.
Some shops push additional services that are often not needed. Rod resizing, line honing and square decking are often part of the schedule and often only needed when an engine has been abused and is really worn out OR if you're aiming for squeezing the very last bit of power from a race engine.
I've only had rod resizing done on Chevy engines that had knocking rod bearings. Same with the line boring. If the crankshaft isn't scarred, I never saw a need to do that and I've never been burned by it. Square decking is a process that corrects casting and machining flaws that cause a range of compression ratios from cylinder to cylinder. This often isn't an issue for engines with compression ratios in the 8.0 to 8.75 zone but it is very important when your compression is higher.
I'm in Northern CA, east of Sacramento. Even up here, machine work isn't cheap unless you know someone. My guy is semi retired so I've been fortunate to get good deals for years.

 

[Photon440]

Old cars didn't have the equipment breakdown as easily accessible as newer cars do.
Documentation only tells you what the original build was. Previous owners may have changed things in the 50 years the car has been on the road.
Originally, there was some type of metal tag attached to the differential cover with the ratio listed on it. If the cover has ever been removed, there is a chance that the tag was lost and not reattached.
You can also remove the differential cover and spin the rear wheels to get the ring gear to rotate. They have a series of numbers in them, the ratio is one of them. Chances are very likely that it is a 2.71 since that was the most common. Pre 1971 Performance oriented cars came with deeper gears with higher numbers like 3.23 and 3.55 but by 1972, reduced emissions and economy were becoming the new trend so the axle ratios started to be scaled back. Not many 1972 and later cars got the aggressive deep axle ratios unless the car had a "towing package". That option was listed on the build sheet. The build sheet was a piece of paper that was essentially a recipe for the options on each car....they were printed prior to assembly for the assembly line workers to read so they could pick the correct parts during assembly. Sometimes they were left in the cars as they went down the line. People have reported them under the carpet, wedged in the seat cushions, above the glove box and other places. They were "trash" back then and an easy way to get rid of them was to just stuff them in the cars as assembly was finished.

Funny, in 1971 Pontiac was advertising that they were installing higher numbered gears to offset lower engine compression and keep acceleration the same.

 

[Curiousyellow71]

How would I check to see what my axle size is? Would the vin have that information?

Its simple to see what you have. Jack the back of the car up. Spin both rear tires(suregrip) one revolution..count the driveshaft turns. Its probably about 2 and 3/4 turns.
If it's 8 1/4 it has a cover that's bolted on the back. If it's a 8 3/4 there is no rear cover, the pig is bolted to the front.

With a one legger rear end you can also leave one tire on the ground and jack up and spin the other 2 revolutions..and count how many driveshaft turns.

 

[Budnicks]

That's the kind of story I'm hoping to come away from this with. I'm sure I'll have my own set of misadventures along the way, it's been awesome hearing about what other guys have done before and how it went for them

 

[Budnicks]

Adam
you need to start a build thread,
or maybe go to the appropriate forum section
there's lots of them here
many of the questions have been asked 100 times
& people answered
you can also use the "Search" function tab, on the top right of every page

this section isn't intended for a Q&A or tech section
it's just the welcome wagon
to get to know each other & share a story (or 3 )
& maybe a few photos (we do love our car ****)

good luck

 

[KiwiKid72]

Welcome from New Zealand, and from another '72 Satellite driver.