Can't take it?

[Cornpatch MO]

440 about 375 Horses, 4 speed, 3:54 sure grip in a 742 differential, Nitto drag radials DOT 275/60/R15. HD Spring leaves clamped, but no pinion snubber. New driveshaft set up for 7290 U joints with the rear one a combo to fit the 7260 differential yoke.
I just proved the 7260 diff. yoke can't take a 35-4000 RPM launch, because I broke it. The combo U joint did not fail, it was the yoke.
Question: will a steel billitt 7290 yoke with the U bolts for the caps ( instead of straps) handle my set up? Is it really neccesary to go to a 1350 U joint driveshaft and yokes? ..............................MO

 

[miller]

Personally, think the 7290 joints would be the ticket, though the 1350s would handle it, too. Just choices.

 

[mmissile]

big-block, stick, sticky tires=Dana 60.

 

[PurpleBeeper]

I believe mmissile is correct. You are on the "ragged edge" of what that rear end will handle. I've had good luck with 440/4spd w/8-3/4", but I'm not running slicks/drag radials. In my opinion, I would at least give the billet differential yoke a chance since it's much cheaper/easier than putting in a Dana. If it breaks again....go Dana.... or run street tires at the track.

 

[Fran Blacker]

You want another 7260 10 spline? Free except for the ride. 7290 u joint came on 4 speed hemi cars. So I'd go with a 7290 yoke.

 

[Cornpatch MO]

big-block, stick, sticky tires=Dana 60.

Yeah, I knew that would be coming ! But I have so much money in my 742 set up that I have to use that. I will rarely race it , and never dreamed the Nittos would get the traction that they do. Looks like I will need to get a taller pinion snubber too. The new HD leaf springs ,even with the leafs clamped, aren't enough. ....................................MO

 

[Cornpatch MO]

I believe mmissile is correct. You are on the "ragged edge" of what that rear end will handle. I've had good luck with 440/4spd w/8-3/4", but I'm not running slicks/drag radials. In my opinion, I would at least give the billet differential yoke a chance since it's much cheaper/easier than putting in a Dana. If it breaks again....go Dana.... or run street tires at the track.

 

[Cornpatch MO]

I believe mmissile is correct. You are on the "ragged edge" of what that rear end will handle. I've had good luck with 440/4spd w/8-3/4", but I'm not running slicks/drag radials. In my opinion, I would at least give the billet differential yoke a chance since it's much cheaper/easier than putting in a Dana. If it breaks again....go Dana.... or run street tires at the track.

Got one ordered along with a stronger (raceing) U joint with U clamps.
Brewers is the BEST! Wayne didn't have them in stock, but he arranged to have them drop shipped to me with next day delivery. ...............................MO

 

[mmissile]

Another issue, is your rear gear. It's loading the driveline a lot harder than a shorter/bigger gear.

 

[Cornpatch MO]

You want another 7260 10 spline? Free except for the ride. 7290 u joint came on 4 speed hemi cars. So I'd go with a 7290 yoke.

Thanks for the generous offer Fran, but I think I have it covered...............................MO

 

[65 3 times]

Yeah, I knew that would be coming ! But I have so much money in my 742 set up that I have to use that. I will rarely race it , and never dreamed the Nittos would get the traction that they do. Looks like I will need to get a taller pinion snubber too. The new HD leaf springs ,even with the leafs clamped, aren't enough. ....................................MO

Cornpatch I have a adjustable pinion snubber off my 489 rear. It's in perfect condition I went to Cal-Tracs. Sen me a PM. Dave

 

[dvw]

I've been pounding on my mid 12 second Challenger for years. Broke a few u joints, front yoke, spider gear, and twisted the stock axle splines. Plenty of runs with slicks. Believe it or not it still has the untouched 8 3/4, 489 case, 3.55 it was built with in 73 (7260 joint)
Doug

 

[Cornpatch MO]

I've been pounding on my mid 12 second Challenger for years. Broke a few u joints, front yoke, spider gear, and twisted the stock axle splines. Plenty of runs with slicks. Believe it or not it still has the untouched 8 3/4, 489 case, 3.55 it was built with in 73 (7260 joint)
Doug[/QUOT


Puzzleing to me why some are getting by with the 7260 joint and mine did not, even without as much abuse on mine. Maybe mine was a combination of different things. Is yours an automatic without trans brake? .................................MO

 

[Cornpatch MO]

Click to expand for my responce..........................MO

 

[dvw]

23 spline 833 4 speed, 2.47 1st . It broke the front yoke when it was running a 2.76 rear for a trip out west. Shouldn't have tried a burnout 500 mIles fromhome, lol.
Doug

 

[Cornpatch MO]

23 spline 833 4 speed, 2.47 1st . It broke the front yoke when it was running a 2.76 rear for a trip out west. Shouldn't have tried a burnout 500 mIles fromhome, lol.
Doug

For sure ! I told wifey ( she was with me) Good thing is , we aren't far from home......................................MO