8 3/4 powr-lok

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DusterJoe410.4

DusterJoe410.4

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I bought a power-lok for my street/strip (mostly strip)71 Duster today, it’s brand new with new Tiimken side bearings. Got it for $325 so I think I got a good deal. I’m curious as to how much horsepower and torque it will take, as it’s going behind a 410 stoker that should make 475+ hp and 500+ ft lbs of torque and will have a 4.30 gear. I previously ran a factory cone type suregrip in my D100 street strip toy and it held up decent but I’ve always heard the clutch type is preferable. What do the masses think, will it hold up good?

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It'll take that and not even sweat. The axles are what you will need to worry about.
 
DusterJoe410.4 said:
I bought a power-lok for my street/strip (mostly strip)71 Duster today, it’s brand new with new Tiimken side bearings. Got it for $325 so I think I got a good deal. I’m curious as to how much horsepower and torque it will take, as it’s going behind a 410 stoker that should make 475+ hp and 500+ ft lbs of torque and will have a 4.30 gear. I previously rand a factory cone type suregrip in my D100 street strip toy and it held up decent but I’ve always heard the clutch type is preferable. What do the masses think, will it hold up good?

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If it's mostly strip have you ever thought of $125 lightweight spool?
 
You will break the caps that hold the power grip in before you break that unit. Over 600 hp I would go to a dana 60. jmho which I really value.
 
DusterJoe410.4 said:
I debated going with a spool but decided to go limited slip because I do plan to drive it on the street locally some (back and forth to work and local shows)
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Of course I do to have a 410 Stroker and drive on the street quite a bit. I have the spool and sure appreciate it on track day. Straight as an arrow every single time...
 
j par said:
If it's mostly strip have you ever thought of $125 lightweight spool?
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I have.... I'm not really scared of a spool on the strip
Jadaharabi said:
You will break the caps that hold the power grip in before you break that unit. Over 600 hp I would go to a dana 60. jmho which I really value.
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BWAHAHAHAA.… "jmho which I really value".... :D I like that!!
 
DusterJoe410.4 said:
I bought a power-lok for my street/strip (mostly strip)71 Duster today, it’s brand new with new Tiimken side bearings. Got it for $325 so I think I got a good deal. I’m curious as to how much horsepower and torque it will take, as it’s going behind a 410 stoker that should make 475+ hp and 500+ ft lbs of torque and will have a 4.30 gear. I previously ran a factory cone type suregrip in my D100 street strip toy and it held up decent but I’ve always heard the clutch type is preferable. What do the masses think, will it hold up good?

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500 ft lb and a 4.30 gear you'll have a hard time keeping the tires under that thing on the street. They won't bite hard enough to test a Sure Grip.
 
DusterJoe410.4 said:
I bought a power-lok for my street/strip (mostly strip)71 Duster today, it’s brand new with new Tiimken side bearings. Got it for $325 so I think I got a good deal. I’m curious as to how much horsepower and torque it will take, as it’s going behind a 410 stoker that should make 475+ hp and 500+ ft lbs of torque and will have a 4.30 gear. I previously ran a factory cone type suregrip in my D100 street strip toy and it held up decent but I’ve always heard the clutch type is preferable. What do the masses think, will it hold up good?

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Couldn't tell you of its limitations, but I'm running one of those from Dr. Diff w/4.10's on my street/strip setup running low 12's. Launches straight every time, no issues other than once in a blue moon I'll get a minor clunk in a turn first of the day, rarely does it actually. Was recommended to use the Ford additive with gear oil. I wouldn't worry one bit or have any doubts about strength.
 
toolmanmike said:
500 ft lb and a 4.30 gear you'll have a hard time keeping the tires under that thing on the street. They won't bite hard enough to test a Sure Grip.
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Yeah I’m sure it will have traction issues on the street, but it’s getting a set of 275/60/15 Mickey Thompson ET Street Pros so hopefully that will help.

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That's a good one. You should be fine. I haven't broke one in the last 50 years.Automatic,stick,slicks, all kinds of gear ratios. Check the torque of the bolts that hold it together before installing.
 
DusterJoe410.4 said:
I bought a power-lok for my street/strip (mostly strip)71 Duster today, it’s brand new with new Tiimken side bearings. Got it for $325 so I think I got a good deal. I’m curious as to how much horsepower and torque it will take, as it’s going behind a 410 stoker that should make 475+ hp and 500+ ft lbs of torque and will have a 4.30 gear. I previously ran a factory cone type suregrip in my D100 street strip toy and it held up decent but I’ve always heard the clutch type is preferable. What do the masses think, will it hold up good?

View attachment 1715411026
Click to expand...

Mostly strip , I would have put a spool in it . I ran one in a hot 406 vega, drove it to work 28 miles each way quite a bit , no problems as long as u don't goose it on a curve and slow down some if caught in the rain. Much cheaper and fool proof. Stronger too ---JMO
 
I had one of the new reproduction powerlocks in an 8 3/4 Dart Sport with a 408 4 speed. It was fine until I added slicks and started to launch at the drag strip by dropping the clutch at 3000. It took 5 or 6 launches like that until it tore the spider gears apart.

With an automatic and on the street you should be fine. If you take it to the track, add sticky tires and launch off a trans brake you will likely find its limitations.
 
d55dave said:
I had one of the new reproduction powerlocks in an 8 3/4 Dart Sport with a 408 4 speed. It was fine until I added slicks and started to launch at the drag strip by dropping the clutch at 3000. It took 5 or 6 launches like that until it tore the spider gears apart.

With an automatic and on the street you should be fine. If you take it to the track, add sticky tires and launch off a trans brake you will likely find its limitations.
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This is definitely a new reproduction Powr-lok, the car will be footbrake with Mickey Thompson Et street radials and a 727. I currently have a 10” B&M 3000ish stall converter but I’ve been eyeing a used TCI 9” “J” converter for it. Hopefully it will be fine.
 
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The first picture is a 8 and 3/4 and a D60 410 ring..
The second picture is my 8 and 3/4 489 case spool...
Like mention I blew the Caps off...
"Where there's a will, there's a way!".. :thumbsup:
 
j par said:
View attachment 1715411152 View attachment 1715411153
The first picture is a 8 and 3/4 and a D60 410 ring..
The second picture is my 8 and 3/4 489 case spool...
Like mention I blew the Caps off...
"Where there's a will, there's a way!".. :thumbsup:
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That's because its a 489, if it were a 742 that would not have happened, the caps are thicker on a 742 because the bearings are smaller.
 
I still think the Dana powerlok is the strongest diff out there, been in use sense the 40's.
 
brian6pac said:
That's because its a 489, if it were a 742 that would not have happened, the caps are thicker on a 742 because the bearings are smaller.
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Are you sure about that? I thought the pinion had a bigger bearing not the ring??
Do you have a picture of the Caps side by side?...
Thank you, just learning...
 
The 742 has the biggest pinion bearing of all and the 489 has the biggest carrier bearings. I sold my last 742 case a couple weeks ago but they are the strongest of all.
 
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