8 3/4 schooling needed

[c_callen]

Im in need of some 8 3/4 schooling. I've tried a ton of searches but can't narrow down an answer.

I have a '64 Polara that already has the axles swapped to '65+ with a 741 chunk and 2.90ish gears. I have a 742 sure-grip with 3.91s I was going to swap in. My question is this, will I need different length axles to do this?

I'm also not opposed to trading that 742 for something set up with 4.30s. I'll mostly be milling around town with the occasional test and tune night. I'll just swap to a highway chunk when I plan on road tripping.

 

[1967coronet440]

No

 

[Bill Monk]

Same length

 

[PurpleBeeper]

Yeah, from what little I know, just swap over the "pumpkins" (aka "chunk"), but in a new gasket/gear lube & run it.

 

[c_callen]

Thanks fellas

 

[wannadrag]

I have a 430 742 suregrip that I will be removing from my Challenger.They will be for trade or sale within a few weeks.PM me if interested

 

[Bruzilla]

Im in need of some 8 3/4 schooling. I've tried a ton of searches but can't narrow down an answer.

I have a '64 Polara that already has the axles swapped to '65+ with a 741 chunk and 2.90ish gears. I have a 742 sure-grip with 3.91s I was going to swap in. My question is this, will I need different length axles to do this?

I'm also not opposed to trading that 742 for something set up with 4.30s. I'll mostly be milling around town with the occasional test and tune night. I'll just swap to a highway chunk when I plan on road tripping.

I don't know if you've done this swap before, but you might want to rethink your strategy. Yes, a center is fairly easy to change, but that's like saying getting smacked in the face hurts less than getting kicked in the nuts... they both hurt.

To change the center you need to raise the car, remove the wheels, remove the axle bolts, pull the axles out, disconnect the drive shaft, remove the center bolts, pry the center off, get the center out without crushing your fingers and making a gooey mess with the gear oil, then reverse the whole process while making sure the play is correct and replacing the lube and friction reducer you lost. It's not a ten minute job you can knock out when you're planning a road trip.

I would suggest settling on a gear ratio that'll balance out your strip and highway needs and install that.

 

[AMX364]

I would start with the 3.91 gear since that is what you have and see where it falls for your general use demands. If you ran a quick change rear it would interfere with your stock gas tank. Myself will be running the 3.23 because I have had and disliked the engine noise level of the 3.55. I also have a set of 4.30 NIB that would have been too much. To change the pumpkin is also more of a 4 hour job, easier to rent a car instead and cleaner.

 

[5.7 hemi]

A 4 hour job to change the pumpkin? Does that include a 3 hour lunch??

 

[Cranky]

A 4 hour job to change the pumpkin? Does that include a 3 hour lunch??

Oh man...yeah, when I was 20 years younger, my record was 45 minutes! Now it would probably take me 45 days! lol

 

[AMX364]

Children, children only going to tear apart part of a sentence? What about what I said about the gearing? Or if you must rip then I would have thought it would have been about renting a car for a trip instead. I do know that grammar is one of many weak points. And yes when I was a stupid kid I did put a 383 block in my mothers trunk, by myself. Using blocks of wood to get enough height. I even thought about checking the Time Labor books, but decided I did not care enough too. Because the real post was about gearing and that is what the OP was asking about. He wanted opinions and that is what I was giving, not facts.

 

[Cranky]

Children, children only going to tear apart part of a sentence? What about what I said about the gearing? Or if you must rip then I would have thought it would have been about renting a car for a trip instead. I do know that grammar is one of many weak points. And yes when I was a stupid kid I did put a 383 block in my mothers trunk, by myself. Using blocks of wood to get enough height. I even thought about checking the Time Labor books, but decided I did not care enough too. Because the real post was about gearing and that is what the OP was asking about. He wanted opinions and that is what I was giving, not facts.

Looks to me like his question was answered in post #2, #3, AND #4! I've been swapping 3rd members out since the mid 70's and rebuilding rear ends since the mid 80's and I have NEVER spent 4 hours swapping out chunks. Wait...I did spend 4 hours swapping out a 3rd member in the early 70's....but it was in a 100 ton crane!! Now that was a RPITA. As for renting a car....I've thought about that too but I think the vast majority of us have a daily driver besides our toys. I did use my toys as a daily driver and so did my wife but we usually always had something else to drive but on the other hand, if we wanted to take one of the toys out on a long haul and it had a 4.30 in it, a 2.76 would get thrown in just so we could do 80 mph without spooling the engine up so high. If your exhaust isn't tight around that area, there's no reason why you can't swap out a chunk in an hour or so and 1 1/2 hours max taking your time! And I put a complete 383 in the spare tire well of my 67 Dart and trucked it to the other side of Houston but had to max out the air shocks just to get the car sitting level. Even the trunk lid came close to closing! It was down more than enough to easily use the inside rear view mirror. I didn't have a truck at the time and didn't really care about the Dart. After all, it wasn't even 10 years old yet and no one really thought if they were going to be worth something in another 30 years lol