At what HP/Tq?

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1973Barracuda

1973Barracuda

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i am finally back from overseas and will have a garage again in a month or so. I am finally going to have the time to put the 6.1 I have in my Barracuda. I currently have an open 3.55 that has to go. I am on the fence about throwing a Dana in. At what Tq level should I ditch the thought of an 8 3/4? 6.1 is currently stock. Will have headers and a tune. MAY go Kenne Belle down the road, but that will be a while I think.

Car will be street, occasional track.
17 inch tires
Rebuilt 46RH


Thanks
 
Unless you run big slicks and other traction enhancement devices you will be fine with a suregrip in that 8.75. You can get upgraded axles from doctor diff probably the weak link of stock pieces.
 
Depends on weight of the vehicle and how it is used.
 
And if you have a clutch,lol
I've been running an 8.75, 3.55-SG nearly continuously since 1999, behind my HO367(6.0l). Car went 93 in the 1/8th in 2004. I have hit it with a CFII clutch at up to 4000(at the strip). Car weighs 3650, me in it..Same oil since 2004,lol. 275s, 295s, 325s. It's the one thing the motor hasn't broke.
Your auto will be easier on it

I'm only running a 230* cam so not a lot of power. But I have run more than 185psi cylinder pressure with aluminum heads, so it makes pretty good torque.

I think my 3.55s are in a 742 case, with a cone type, rebuilt and tuned by myself. I got them cheap, cuz they whined. I adjusted the pattern a bit,and they still whine. But I have to listen hard cuz most of the time I just hear those raucous Dynomaxers and full length dual 3s,lol. I sold them once to a guy with an E-body Barracuda. ...... but they were way louder in his car.It seems the E's are bit of a mega-phone back there. So I bought 'em back. They work well with my 3.09 low and overdrive.
 
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mod5v said:
Unless you run big slicks and other traction enhancement devices you will be fine with a suregrip in that 8.75. You can get upgraded axles from doctor diff probably the weak link of stock pieces.
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Put real h.p. in front of an 8 3/4, and u`ll start stripping ring gears too. A back braced , good axle, Detroit locker (if they make them for the 8 3/40, would hold up well I think . Unless it`s really hooked up and u got 750 horses or more.
 
A couple hundred passes at 3050lbs with an 8 3/4 no brace, Richmond gears and Strange axles. 10.90s rearend was still perfect when I sold the car. That being said.... I run a Dana now. I would rather over-build the drivetrain and NEVER have to think about it again.
 
So, the basic consensus is I will be fine with a 8 3/4. Good, that saves me a ton of cash.

Now just to find a reasonable priced chunk.
 
rumblefish360 said:
Depends on weight of the vehicle and how it is used.
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Rumble, almost all street work for this car. I don’t have the bug for drag racing, at least not yet. I drive this car a good bit. And with a new hemi and AC, will probably do some road trips.

Weight of the car, not exactly certain. Stock 73 Barracuda. Will save a few pounds with the hemi as I understand. Maybe 3600 ish?
 
Mine is 3650 according the the reggie. The only lightening parts were the typical engine parts and no carpet or head liner.

Born a 340/4spd. (Didn’t get it that way.)

Built to 360’s for it. Street strip trim, it ran mid to low 12’s at the rare track outing with the “12 second” MP combo. So it wasn’t a super power house engine. I had just made the move to a larger mechanical cam for more rpm. Just haven’t had it out since but for a couple of quick run around the block tests.

Though on the run, (street or strip) shift were clutch press and side step so the pedal would slam up on gear change. Foot still on the floor.

I used to be good with the stick. Sometimes people would ask me what shift kit I had in it. They didn’t beileve it was a manual.
 
Mopar-Man said:
A couple hundred passes at 3050lbs with an 8 3/4 no brace, Richmond gears and Strange axles. 10.90s rearend was still perfect when I sold the car. That being said.... I run a Dana now. I would rather over-build the drivetrain and NEVER have to think about it again.
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I started breaking one every other week end, back in the day, went to a dana 60 , problem over. U need to pull the 727 and check it every time u blow a rear too. Can u say , trans explosion !??! I can !
 
Id say 500hp is starting to reach the limit, it will take every bit of 400 horses you can throw at it trust me i know lol
 
Check out Thumperdart over at moparts and his car.

Runs low 6's and 9.7x iirc at 3100# with an 8.75 for years. 6.15 @ 112.05 and more in it!
 
I am just looking to do the “buy once, cry once”if it fits with my combo. Sounds like I am good until “if/when” I do the supercharger.

Decisions decisions
 
famous bob said:
I started breaking one every other week end, back in the day, went to a dana 60 , problem over. U need to pull the 727 and check it every time u blow a rear too. Can u say , trans explosion !??! I can !
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Yes! I broke a rearend in my other car and sent the driveshaft throw floor tunnel. It broke everything all the way to the converter! LOL.
 
crackedback said:
Check out Thumperdart over at moparts and his car.

Runs low 6's and 9.7x iirc at 3100# with an 8.75 for years. 6.15 @ 112.05 and more in it!
Click to expand...
crackedback said:
Check out Thumperdart over at moparts and his car.

Runs low 6's and 9.7x iirc at 3100# with an 8.75 for years. 6.15 @ 112.05 and more in it!
Click to expand...
1/8 mile?
 
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