Whos running over 700whp on an 8.75?

-
70DusterDev

70DusterDev

Well-Known Member
Joined
Jul 22, 2008
Messages
408
Reaction score
316
Location
Bethel, Vermont
I blew the caps up on my 8.75 at the strip this fall after getting my car finished and tuned, so I got a complete new Yukon 3rd and am going to replace the broken caps with the billet ones as a spare. (found out about the caps after I bought the new 3rd)

We set my car at 750whp this summer because of running out of injectors/pump, but it made 779 with maxing the injector duty cycle. I'm swapping injectors and pumps this winter to go back and break over 800 hopefully.

I have a dana 60 and all the stuff in a cart from Dr. Diff to build the 60 to swap into my car, was just curious before I do if anyone is running an 8.75 with with big power or if I should just do the 60. I also have someone lined up to buy the 8.75 for the $1600 I spent on the 3rd (nevermind the cost of chromo/green bearing shafts). Just sucks I'll have to have my driveshaft cut down for the 60 (its already 1350 joints) and I'll have to move my 4 link mounts on the chassis which is fine since I did all the fab myself, it just adds more to the to do list with a 60. Its a 70 Duster. Probably weighing around 3400lbs or so.

Duster.jpg
 
I'm thinking the same thing. Just one of those things it helps to hear someone else say it to make myself not take the easier way out and blow up the 8.75 again lmao. I will add this is mostly a street rig.
 
you could have someone like Currie build you a braced, bad *** 8-3/4 housing and your Yukon chunk would probably survive. Or go to a ford 9” and possibly keep your mounting points on the car the same. But you definitely need to step up the rear end game. You’re in big boy hp territory now.
 
Yeaahh I have a 9" housing kicking around too, but I figured if I have to do the work to narrow stuff anyways I might as well do the 60 with 35 splines and never worry again. Especially since I can get the housing ends to weld on the 60 and retain my disc brakes with the ebrake cables etc.
 
The harder you get on it and the better the traction, the sooner you'll break the 8 3/4. Don't forget that it will help preserve your trans as well - if it's a 727.
 
Sounds like you'll be able to sell the 8-3/4 for close to what the Dana 60 will cost you. Easy decision in my book.

Why will you have to move the 4-link mounts?
 
The D60 is large. I’m not sure how low you plan to make the car but it’s a thought to consider.
 
mopowers said:
Sounds like you'll be able to sell the 8-3/4 for close to what the Dana 60 will cost you. Easy decision in my book.

Why will you have to move the 4-link mounts?
Click to expand...

When I talked to Bill Reilly about doing the 60 swap since its his kit he said the upper mounts on the bar I welded to the car have to be moved further out because of the width of the center section. Idk why I can just use more triangulation. I'm going to call him and ask him that.
 
TT5.9mag said:
The D60 is large. I’m not sure how low you plan to make the car but it’s a thought to consider.
Click to expand...

It definitely is large. But I'm not going to run the car any lower than in the picture I put in the first post. I hope it clears my gas tank, but I've seen posts of ppl putting 60s in dusters, so I'm assuming it will.
 
I blew the Caps off my 8 and 3/4 and just built a Dana for the same money I had into the 8 and 3/4 and never looked back...
 
Are your upper 4 link bar tabs welded on top of the 8-3/4? Or are they on the axle tubes? The D60 has a cast center housing and welding to it is specialty type welding scenario. Nickel rod type stuff. You’d have to move the tabs off the center section and down on to the tubes. Reducing the angle of the upper bars.
 
TT5.9mag said:
Are your upper 4 link bar tabs welded on top of the 8-3/4? Or are they on the axle tubes? The D60 has a cast center housing and welding to it is specialty type welding scenario. Nickel rod type stuff. You’d have to move the tabs off the center section and down on to the tubes. Reducing the angle of the upper bars.
Click to expand...

No they're welded to the tubes. So I'll need new mounts on the 60. Thats for sure, but Bill said the Chassis side mounts need to be brought out as well instead of just better triangulation. I know in our rock crawlers the more triangulation the better.
 
7DB300C2-6DF2-4CF4-B85B-9DBE8C87BD4B.png

Yea I went back to your build thread and looked. More triangulation is better for stability but I see no reason really why you’d have to change the mounts on the car. You should be able to set up the d60 with the same mount locations as the 8-3/4.
 
Good times!!!..
I had just taken out a fox body Ford in the first round and was lined up against his brother and another Fox body... I let go the clutch and it lurched forward and that was about it...
20151128_141857.jpg
 
TT5.9mag said:
View attachment 1715844071
Yea I went back to your build thread and looked. More triangulation is better for stability but I see no reason really why you’d have to change the mounts on the car. You should be able to set up the d60 with the same mount locations as the 8-3/4.
Click to expand...

I agree. Leaving the mounts on the car where they are will only make my triangulation better
 
TT5.9mag said:
View attachment 1715844071
Yea I went back to your build thread and looked. More triangulation is better for stability but I see no reason really why you’d have to change the mounts on the car. You should be able to set up the d60 with the same mount locations as the 8-3/4.
Click to expand...

Just talked to Bill. The reason for the new bar is because the bar is so close to the axle front to back that the angle is really steep and he said there may be interference from the diff itself and the links. Which makes sense because the upper links are very short. Welding that tube in wont be too big of a deal though.
 
70DusterDev said:
Just talked to Bill. The reason for the new bar is because the bar is so close to the axle front to back that the angle is really steep and he said there may be interference from the diff itself and the links. Which makes sense because the upper links are very short. Welding that tube in wont be too big of a deal though.
Click to expand...
Makes sense.
 
I would go Ford 9"
Cheap, plentiful.
Easy gear swap like a 8 3/4.
Multitude of housings with whatever reinforcements you want or could need.
Heavily supported by the aftermarket.
 
I have been doing this a long time = My vote is to put in the
Dana for sure. I used to break plenty of 8 3/4 stuff with 3400 Lbs
with a 4 Speed and 550 HP!!

No problem with the Gas tank in my dusters/demons
 
Dana67Dart said:
I would go Ford 9"
Cheap, plentiful.
Easy gear swap like a 8 3/4.
Multitude of housings with whatever reinforcements you want or could need.
Heavily supported by the aftermarket.
Click to expand...

My only gripe with the 9" is the 3rd member alone costs more than I can build the whole 60 for basically. And the 60 is definitely strong.
 
You must log in or register to reply here.
-

Back
Top