Yes, I think that's them. I bought something from them a few years back & was quite satisfied. Nice people.
Smokey burnouts..
- Thread starter justanotherguy
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#41
Well-Known Member
Chrysler put the 8-1/4 behind the 383 2bbl in earlier year cars, so I would not be surprised if the 8-1/4 in your car is original equipment assuming it is a car coded for 2bbl 400. A 4bbl car would have originally had an 8-3/4 axle.
The good news is that you should be able to spin a tire with a good tune and a little power braking. I think your goal of doing burnouts is easily obtainable without investing in axle upgrades, though it is 10x more fun when you spin both tires.
The good news is that you should be able to spin a tire with a good tune and a little power braking. I think your goal of doing burnouts is easily obtainable without investing in axle upgrades, though it is 10x more fun when you spin both tires.
justanotherguy
Well-Known Member
I gotta say, that's pretty much the goal. The elusive 2 wheel peel. I guess I've been looking for a 8 3/4 because everyone says they are easier for gear changes and more sturdy. Would it be worth just upgrading my current rear end? If so, what would I want to start with to beef it up?
justanotherguy
Well-Known Member
And also, thanks everyone for your comments so far.
#41
Well-Known Member
Your description of the current idle problem and the fact that you cannot spin a single tire suggests that tuning and/or repair is necessary before anything else. First step - tune/repair and get one wheel to spin.
Next step, after you get some power on hand, any axle upgrade should involve an 8-3/4 (for the reasons people have stated).
justanotherguy
Well-Known Member
For the idle problem, Is it possible I've got a vacuum leak or the hoses aren't hooked up properly to the carb? Forgive the dumb question...never had to deal with this problem before.
Moparfever65
Well-Known Member
Definitely give it a tune first and check it with a vacuum gauge. The stalling issue can be a vacuum leak, timing and mixture adjustments, or could have had the cam swapped without updating the torque converter. You didn't mention what gears are in it now. Easy enough to figure out. Don't go changing things until you know what you have. Otherwise you're wasting time and money. When all else is figured out, a higher stall torque converter would get you what you want.
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Here's a rebuilt 8 3/4 w/3.55 Suregrip for $850 in Vernonia. The same guy has a couple of rebuilt 3.23 Suregrips as well.
Rebuilt Mopar 3.55 Suregrip 8 3/4" - auto parts - by owner - vehicle automotive sale - craigslist
#41
Well-Known Member
Yes, and yes. Also timing and a myriad of other things to check and sort out as mentioned here by others. There are some good basic tune and diagnostic video's on Youtube including finding and stopping vacuum leaks that can get you started.
justanotherguy
Well-Known Member
Great suggestions, everyone. I'll get to checking the timing and vacuum and report back.
As far as the torque converter, I'm almost positive it wasn't changed when the cam was installed. Can't say for sure but with the history of the car, the previous owner use to trade work to have things installed. I'm guessing he just had whatever cam installed without changing anything else. He never mentioned changing the gears, so I'm assuming they are 2.xx. whatever would have originally been offered by Plymouth for the combination.
That is real good advice to check what I already have before buying anything else. I've got much work to do here, gents. I Appreciate it!
As far as the torque converter, I'm almost positive it wasn't changed when the cam was installed. Can't say for sure but with the history of the car, the previous owner use to trade work to have things installed. I'm guessing he just had whatever cam installed without changing anything else. He never mentioned changing the gears, so I'm assuming they are 2.xx. whatever would have originally been offered by Plymouth for the combination.
That is real good advice to check what I already have before buying anything else. I've got much work to do here, gents. I Appreciate it!
Kraig Jorgensen
Member
Looks like an 8 .25 rear end ...the 8 3/4 would have the bolts on the other side and no removable cover..
Detective D
Well-Known Member
Your car is a 73 B body.
Starting in 73, the spring spacing is different then earlier.
However, Chrysler maintained that spacing until 1979.
This means an axle from a 79 Cordoba will fit under your car. It also means instead of looking for a 1 year only(maybe 2, some might be found on 74's) 8.75" rear axle, you can look for a 9.25" rear from basically any 2 or 4 door b body until the end of the decade.
Hint: police cars came with a 9.25" sure grip 3.23" rear.
But really any that fit, in any gear ratio works. Why? Because the 9.25 has gears everywhere. Even using something as new as a set from a 90's truck, you can drop it in if you look up how to modify the c clips to fit your axles.
But honestly, if you keep an eye out for 70's 9.25's out of a cordoba, or coronet, or (late in the decade) fury or monaco(not earlier, c body till 77 with those) I am sure you can find one pop up. Stronger then the 8.75, (old guys all gasp!) not that you will need to worry about that with a mostly stock 400. If you are dead set on a 8.75 I have one with 3.23 in it that needs a rebuild, you just need to drive to WI to come pick it up
Your warmed up/dies at idle issues may be torque converter, might be a bad vacuum leak somewhere, including the brake booster. You could try plugging the brake booster line when it is warmed up and see if it still dies to rule that out(not while driving it silly) Otherwise timing might need adjusted, if someone did a cam, who knows if they actually redid the timing right.
Starting in 73, the spring spacing is different then earlier.
However, Chrysler maintained that spacing until 1979.
This means an axle from a 79 Cordoba will fit under your car. It also means instead of looking for a 1 year only(maybe 2, some might be found on 74's) 8.75" rear axle, you can look for a 9.25" rear from basically any 2 or 4 door b body until the end of the decade.
Hint: police cars came with a 9.25" sure grip 3.23" rear.
But really any that fit, in any gear ratio works. Why? Because the 9.25 has gears everywhere. Even using something as new as a set from a 90's truck, you can drop it in if you look up how to modify the c clips to fit your axles.
But honestly, if you keep an eye out for 70's 9.25's out of a cordoba, or coronet, or (late in the decade) fury or monaco(not earlier, c body till 77 with those) I am sure you can find one pop up. Stronger then the 8.75, (old guys all gasp!) not that you will need to worry about that with a mostly stock 400. If you are dead set on a 8.75 I have one with 3.23 in it that needs a rebuild, you just need to drive to WI to come pick it up
Your warmed up/dies at idle issues may be torque converter, might be a bad vacuum leak somewhere, including the brake booster. You could try plugging the brake booster line when it is warmed up and see if it still dies to rule that out(not while driving it silly) Otherwise timing might need adjusted, if someone did a cam, who knows if they actually redid the timing right.
I just bought a new Strange 60 for my 71 Charger R/T. $3019 shipped.
justanotherguy
Well-Known Member
Finally corrected the stalling issue. There was a massive leak from the carb to the pcv valve. Replaced the hose and pcv and she's a happy engine for the time being.
I also managed to finally find an 8 3/4. It's got a 489, 3.91 gears, suregrip and is in good shape. Plan to reuse my brakes from the 8 1/4, slap her in and go.
Anyone have any tips for the swap? The 489 has what appears to be a 7260 yoke. Hoping it will just bolt on up to the drives haft with no mod required.
I also managed to finally find an 8 3/4. It's got a 489, 3.91 gears, suregrip and is in good shape. Plan to reuse my brakes from the 8 1/4, slap her in and go.
Anyone have any tips for the swap? The 489 has what appears to be a 7260 yoke. Hoping it will just bolt on up to the drives haft with no mod required.
Detective D
Well-Known Member
8.25 to 8.75 is not a direct bolt in.
As I mentioned above, 8.25 to 9.25 basically is.
Your driveshaft will not be the right length, you will need to find one or modify yours.
I can't speak to the brakes to know if they will swap over from 8.25 to 8.75. Again, a 9.25 they will.
justanotherguy
Well-Known Member
Didnt buy a 9 1/4. ♂
From all the searching I've done, seems like most people have gotten lucky with the driveshaft length. Not saying I won't have issues, but ya never know. What makes you say the driveshaft will absolutely need modding? Looks like it's only a .66" difference according to an axle centerline to yoke chart.
From all the searching I've done, seems like most people have gotten lucky with the driveshaft length. Not saying I won't have issues, but ya never know. What makes you say the driveshaft will absolutely need modding? Looks like it's only a .66" difference according to an axle centerline to yoke chart.
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RemCharger
Well-Known Member
I did a Volare 8.75 swap and put all the original brake stuff on. Didn't even Crack the hydraulic system.
The 8” 1/4 was as mentioned installed also on 400 2 bbls since the power is too similar to the “mighty 318” LOL.
I recall even have seen some 400HP car being uploaded/published around getting a 8” 1/4!!!
About the driveshaft lenght… the Parts Manual Catalog gets a table about the right lenght (and even yokes) for each body, axle and engine/transmision combo. Pretty sure I have posted from the 71 &/ 74 catalogs somewhere. But is true that I know lot of ppl making those changes without consider the lenght diff and talking about REGULAR street use without any abuse, they don’t get any problem keeping the one existing on car. Mostly sure didn’t even know about the lenght diff so playing with the ignorance they are into the limits LOL.
About brakes… I’m pretty sure all interchanges, just that some cars get 10” drums and others 11” drums, but on either size, the plate mounts on the same pattern no matter the axle housing.
I recall even have seen some 400HP car being uploaded/published around getting a 8” 1/4!!!
About the driveshaft lenght… the Parts Manual Catalog gets a table about the right lenght (and even yokes) for each body, axle and engine/transmision combo. Pretty sure I have posted from the 71 &/ 74 catalogs somewhere. But is true that I know lot of ppl making those changes without consider the lenght diff and talking about REGULAR street use without any abuse, they don’t get any problem keeping the one existing on car. Mostly sure didn’t even know about the lenght diff so playing with the ignorance they are into the limits LOL.
About brakes… I’m pretty sure all interchanges, just that some cars get 10” drums and others 11” drums, but on either size, the plate mounts on the same pattern no matter the axle housing.
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