Rear End Gear swap
#1
Mopar Fanatic
Thread Starter
Rear End Gear swap
So I know I have talked about this before, I am running a 2:94 or 2:97 on my 68 Dodge Coronet 440, I am planning to swap it out when I get home from work towards the end of February 1st of March,
I am looking at 3:73s or 3:91s Now I found a guy that has a 3:91 Ring and Pinion set new or NOS never been used and I might be able to get it for $150. Now my buddy said I also need the 8-3/4 Master Bearing Set for the swap, I am running a 489 case housing.
What else would I need and what is your thoughts on my project, I am just going to tear into it and drink beer while I do it, I figure between You tube,Books, And you guys i can get it done.
I am looking at 3:73s or 3:91s Now I found a guy that has a 3:91 Ring and Pinion set new or NOS never been used and I might be able to get it for $150. Now my buddy said I also need the 8-3/4 Master Bearing Set for the swap, I am running a 489 case housing.
What else would I need and what is your thoughts on my project, I am just going to tear into it and drink beer while I do it, I figure between You tube,Books, And you guys i can get it done.
#2
Mopar Lover
Kind of depends on How much Hwy? and How much City Driving? And What the compromise will be for the performance your looking for?
I Like a 3.91 for all around....
I like a 4.10 For hot Rodding
I like a 4.30 for racing...
Oh.. And Sure-Grip it for sure...
I Like a 3.91 for all around....
I like a 4.10 For hot Rodding
I like a 4.30 for racing...
Oh.. And Sure-Grip it for sure...
Last edited by RacerHog; 01-16-2017 at 03:15 PM.
#3
Super Moderator
I'm a fan of 3.73s for a car that gets highway use and never hits the dragstrp, 3.91s if you have taller rear tires.
#4
Mopar Lover
ray -
I'm switching from 3.23s to 3.90's. I'll let you know how it goes in a month or so.
Since I do a bit of highway driving, the only reason I'm going ahead with the swap, is because there's a "fail safe", a viable over-drive unit on the market.
What I would do first is go through one of the gear ratio calculators and see what kind of rpm you'll be running at your normal driving speeds.
Archer
I'm switching from 3.23s to 3.90's. I'll let you know how it goes in a month or so.
Since I do a bit of highway driving, the only reason I'm going ahead with the swap, is because there's a "fail safe", a viable over-drive unit on the market.
What I would do first is go through one of the gear ratio calculators and see what kind of rpm you'll be running at your normal driving speeds.
Archer
#5
Mopar Fanatic
Thread Starter
I want something snappy.
I am just trying to figure out how mus=ch its going to cost me and what I will need.
#7
Super Moderator
4.10s were the gears back in the day but so was thirty cents a gallon premium. I've run 4.10s with a fairly mild cam and gotten seven mpg on the highway and with a fairly wild cam you could watch the gas gauge move on the highway!
#8
Mopar Lover
Good.... 3.91's.... Good Choice.... Now just keep all the low end torque and you will be good to go...
Need some Pricing on the diff stuff.. >>>>> http://www.doctordiff.com/
Might help you pencil a price together>>>> http://www.mopartsracing.com/parts/dtrain.html
Lot out there to choose from...
Need some Pricing on the diff stuff.. >>>>> http://www.doctordiff.com/
Might help you pencil a price together>>>> http://www.mopartsracing.com/parts/dtrain.html
Lot out there to choose from...
#9
Mopar Fanatic
Thread Starter
Good.... 3.91's.... Good Choice.... Now just keep all the low end torque and you will be good to go...
Need some Pricing on the diff stuff.. >>>>> http://www.doctordiff.com/
Might help you pencil a price together>>>> http://www.mopartsracing.com/parts/dtrain.html
Lot out there to choose from...
Need some Pricing on the diff stuff.. >>>>> http://www.doctordiff.com/
Might help you pencil a price together>>>> http://www.mopartsracing.com/parts/dtrain.html
Lot out there to choose from...
My wife said I can spend 5K on the car this spring and I want to use it wisely.
#10
Mopar Fanatic
Thread Starter
#11
Super Moderator
#13
Super Moderator
I should be so lucky.....'
#14
Mopar Lover
I would get a full master kit for all new differential bearings.
I would get new ring gear bolts.
For a 489 definitely one of these http://www.doctordiff.com/8-3-4-489-...liminator.html
I would get new ring gear bolts.
For a 489 definitely one of these http://www.doctordiff.com/8-3-4-489-...liminator.html
#15
Mopar Fanatic
Thread Starter
I would get a full master kit for all new differential bearings.
I would get new ring gear bolts.
For a 489 definitely one of these http://www.doctordiff.com/8-3-4-489-...liminator.html
I would get new ring gear bolts.
For a 489 definitely one of these http://www.doctordiff.com/8-3-4-489-...liminator.html
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