Sweet, I need to move where you are as that would never happen out here!
I should have been smart like Jpar and just gone the 60 route from the beginning when I pulled the 7 3/4....
Whos running over 700whp on an 8.75?
- Thread starter 70DusterDev
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I should have been smart like Jpar and just gone the 60 route from the beginning when I pulled the 7 3/4....
There are 9s everywhere here cheap and sometimes free.
33IMP
Well-Known Member
I probably had under a grand in one of my nines. A narrowed housing was in the car as a roller when I bought it, got a new spool,and used gears and nodular case from a good friend who owned a one man rear-end shop. He specialized in nine inch fords, he bled Ford blue. New 33 spline strange axles, and JFZ disc brakes. I doubt I could build it again for under two grand today.
Yes but the Street car 4 spd Demon will be first completed. I post the car when its started. We are doing both drive lines first.
421 for the track car and a 416 iron head for the street car
3 pinion bearings on a 9 and a separate pinion carrier . The better rear of all choices . If I wouldn't have so many 8 3/4's I would be using a 9
70DusterDev
Well-Known Member
Did you buy the actual alignment inserts and rod? Or did you just put the shafts and bearings in the ends and use garage tools to get it close and weld it up? I was thinking I'll assemble it all and cut 4 windows in a piston ring compressor and use that to wrap around the housing and the new housing end to tack weld it.
70DusterDev
Well-Known Member
I've never heard of the Soft Lock? The 800hp twin disc performed incredibly well on the road. Felt like a stock clutch. They told me the 1200 should be a similar feel? I'll look into the Soft Lock
mopowers
Well-Known Member
I had a buddy weld the ends on since he had the appropriate end pucks and solid alignment bar. Since the tubing is so thick, I wouldn't have a problem doing it your way either. Just keep in mind the housing ends likely have a different OD than the axle tubes, so you'll have to account for that somehow.
70DusterDev
Well-Known Member
Yeah, I figured they would so I was going to shim them with something to get it close. If its off by a few thousands I'm sure it'll be fine. At the end of the day, its the bearings that take any forces of misalignment and are cheap and easy to replace. But I'm still going to get it as close as possible.
Rat Bastid
Dunamis Metron
If you really want to understand what McLeod calls the soft lock type of clutch you can call Advanced Clutches in Idaho a talk to Rob. He can fill you in on why what you have isnt what you think it is. After that you can call Black Magic Clutches and talk to Cale or Tinsey. Either one. That will help you learn that getting a clutch “locked up” isn’t the best way to do it. Certainly not getting it locked up as soon as the pedal is out any way.
j par
Well-hung Member
Well let's not go running off and calling Jpar smart...lol.
First I did get rid of my seven and a quarter first thing because I had blown those up before. I got a eight and a quarter and ran that for quite some time. After I got the Stroker motor I felt I was going to break it so I sold it before it broke and then build the 8 and 3/4 and after 20 passes promptly broke it LOL then I did the Dana 60 and never look back.. needless to say there was some trial and error...
j par
Well-hung Member
Have you looked into a clutch tamer?..
You do actually want just a tick of slippage.. you can adjust that slippage in the driver's compartment on the fly according to conditions of the day...
j par
Well-hung Member
70DusterDev
Well-Known Member
I sure havent! But I'm going to start with a clutch thats at least rated for the HP. When I pulled the clutch out there were hot spots everywhere.
j par
Well-hung Member
Grant goes by weed burner here on the forum. I haven't seen him in quite some time out here but I've talked to him plenty of times and he's real easy going. If you look up clutchtamer.com or something like that you'll see all the articles.
I put one in my car just about the time I stopped drag racing.. I guess you really never stop and not to say I won't be out there again but I've just moved on to other things...
The reading in the articles get pretty complicated but more so it's just trying to get that half a disc of slip or quarter disc of slip at the hit. You're trying to not shock the tires and get them to burn but you're also not trying to shock your drivetrain as well it's that perfect slip of the clutch that you're looking for...
Being able to dial that in right at your dash is a pretty cool option...
Having a pre-adjusted slippage in your clutch or having to go under the car and adjust it seems like a bit too much work to me...
Rat Bastid
Dunamis Metron
Buying a clutch based on HP is like buying cylinder heads or a carb based on CFM. It’s the wrong way to do it. Phone calls are cheap.
A friend of mine Denver Fink Had a Gremlin small block 4 spd with a 410 Dana out of a 69 b-body. Hard launch at a stop sign. The clutch unit broke and the car made a hard right. Through the front bay windows of a house .
He stopped with the tv facing him at the end of his hood with Bananza playing. The old guy sitting to his left on a recliner outside his drivers door and his wife sitting to his right outside his passenger door .
The old guy yelled what do you want! He never got up kept sitting there with his wife until the police came. Red'sy said the looks on their faces was such that he sat there laughing . he couldn't get out of the car the chairs were holding the doors closed .
He stopped with the tv facing him at the end of his hood with Bananza playing. The old guy sitting to his left on a recliner outside his drivers door and his wife sitting to his right outside his passenger door .
The old guy yelled what do you want! He never got up kept sitting there with his wife until the police came. Red'sy said the looks on their faces was such that he sat there laughing . he couldn't get out of the car the chairs were holding the doors closed .
j par
Well-hung Member
Listening to gurus's expensive... LOL...
turbodart68
Well-Known Member
My Duster makes 860 to the tire through an 8.75. With parts from the 90’s it lasted 23 years with lots of hits. I think the 8.75 gets a bad rap. With that being said, if i was starting from scratch it would be 9” all the way. Its just stout and parts availability is insane. The only bummer is that to get any Mopar low you need to cut the floor for the housing to clear. Otherwise it has to be stock height. I like mine low so its not really an option.
The downfall of an 8 3/4 is the housing flex. The flex causes the axles to crack the carrier caps. Most using the 8 3/4 use billet caps. I found a brace on the housing worked for me. 829 to the crank 742 carrier with a spool running 456 gears and a loose 5500 stall. Car weighed 3650 with no driver. Same rear in the car for many years.
The brace only went to the u-bolts. We will be cutting a early heavier truck housing to T-body width and running the braces to the axle flanges then put tubes through them for the u-bolts.
Our early Valiant also has a 8 3/4 same carrier and gears but runs a faceplated liberty Hemi 4spd. The car is getting a B1 big block But the car only weighs 2400 . We'll see what the rear takes with that. Both are leaf spring cars.
In all my years of hammering on 8 3/4's on the street I only ever broke 2 on holeshots. They were 741's with running tall tires in my manual trans 1971 power wagon and they broke the pinion clear off from spring wrap.
I never broke a 742 . The early big block block cars all had 8 3/4's I would take them to 3000 and higher then push the low gear button.
The brace only went to the u-bolts. We will be cutting a early heavier truck housing to T-body width and running the braces to the axle flanges then put tubes through them for the u-bolts.
Our early Valiant also has a 8 3/4 same carrier and gears but runs a faceplated liberty Hemi 4spd. The car is getting a B1 big block But the car only weighs 2400 . We'll see what the rear takes with that. Both are leaf spring cars.
In all my years of hammering on 8 3/4's on the street I only ever broke 2 on holeshots. They were 741's with running tall tires in my manual trans 1971 power wagon and they broke the pinion clear off from spring wrap.
I never broke a 742 . The early big block block cars all had 8 3/4's I would take them to 3000 and higher then push the low gear button.
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