8 1/4 rear end

-
G

gremlin

268Darts
Joined
Oct 13, 2005
Messages
618
Reaction score
8
Location
Houston
I was reading the new Mopar Muscle street shoot out, and read about a guy running 10.66 NOS and 11.s on the motor in a 340 4 speed 4:10 geared Duster. He says he runs a spool and does occasional street duty. Most people here say the 8 1/4 isn't good for much horsepower. So, what breaks? Is the spool why his rear lasts? Is he a member of this board?
 
The Achilles heel of the 8 1/4" is the C clips that retain the axles. If you break an axle, there is nothing to keep the axle in the housing. I would imagine the guy is running C clip eliminators with a spool.
 
abodyjoe said:
could it have been a misprint?
Click to expand...

I don't know. It was a 74 340 Duster. I thought the 340 wasn't available that year. But when you consider that there were a couple of 440-6 cars built in 72, a 74 340 car isn't out of the question. Anyhow, the article does say it has an 8 1/4 with strange spool. I was kinda hoping he is a member here, and could answer the question.
 
A spool is designed for racing and dosen't give up when the power is put to it so easy like a street duty rear end. The 8-1/4 is short sold by most. However, running those times, I myself would look to something stronger. I'm not an expert in this area.
 
I would like to know how many passes are on that rear. I've heard that big block torque is the big killer of 8 1/4s. Tha manual tranny has got to be hard on it though.
 
C-clip eliminators might help,but running those times?He,s treading on thin water. trust me,he,s gotta be pushing well over 500hp.
 
There was an article a few years back in one of the mopar rags that had an article on building an 8.25. They said you could build one to survive behind a 600 HP sb with an automatic. I do remember the cast aluminum cover with the jack bolts to support the bearing caps was one of the key items to making the center section survive.
 
dgc333 said:
There was an article a few years back in one of the mopar rags that had an article on building an 8.25. They said you could build one to survive behind a 600 HP sb with an automatic. I do remember the cast aluminum cover with the jack bolts to support the bearing caps was one of the key items to making the center section survive.
Click to expand...

Yah, I don't remember what issue it was in either, but the aluminum cover was the LPW Racing Products that I mentioned above. Plenty strong enough for anything I'll ever run, and alot cheaper too.
 
I've been looking around and found a guy locally that has an A-body 8 1/4 rear for sale for $100. This thread pretty much answered my question. It'll be behind a mildly rebuilt 440 with an automatic transmission. I don't plan on making huge horsepower for a while, so I think it'll work for me. Plus it's only $100 and it'll bolt right in.
 
I CAN SEE $100 DOLLars Being cheap,but bEHINd a 440 you should run c-clip eliminators.I broke an axel at the track and the wheel axel with drum past me.I was very lucky that I didn,t cave my 1/4 panel.Just a thouGhT,ALSO just broke a .489 C.SECTION BUT IT WAS OLD AND USED.HAD BEEN LAYING AROUND FOR18 YEARS.be careful
 
I have a 8 1/4 that I had 8 3/4 ends put on with resplined 8 3/4 axles with the larger 29 spline, 1997 and up differential. I haven't put it in a car yet though. The current SRT8 cars use an even smaller 8" rear. Including the new 6 speed..
 
You must log in or register to reply here.
-

Back
Top