need help! I don't know nothin' about gears!

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Hyperballsmcgee

Hyperballsmcgee

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I have a 74 scamp with a 340 swapped in it and I'm wondering why I'm going slow.

- edelbrock 4bbl, not sure what cfm
- magnum cam
- Accel super stack coil
- edelbrock performer rpm intake
- it's one of them low compression 340's.

currently have a tf727 but plan on swapping for a 4 speed manual.

rear end sucks. all I know is that it's tiny, and the motor screams but the car doesnt want to go anywhere and she spins the one wheel wonder, the one tire fire, whatever you wanna call it.

I wanna spin both wheels and actually get somewhere. slowly building the car for either 1/4 or 1/8 while still cruising on the weekends.

I know this isn't alot of info, but it's difficult to ask about tech when you don't know what to ask. so any help you can give is greatly appreciated. currently talking to another member about getting an 8 1/4 complete rear minus gears.
 
If you are going to the expense of changing the rear use a 8.75 because it will allow you to changes gear ratios easy and there are more parts and options available.
I paid $250.00 for the bare housing for my duster.
$333.00 for axles from Dr. Diff.
Re-used the stock brakes from the rear end under your car.
Around $500.00 or so for a used sure-grip rear with the ratio you want.
 
Put an 8 3/4'' rear in it with some 3:91 gears and a sure grip and it will be a different car.
It's not the little rear end's fault, it's the highway gears and the lack of a sure grip.
The 7 1/4'' in it is too wimpy to last if you are going to beat on it much longer.
The 8 1/4'' is good for a street application, but you say you are going to run it at the strip, so i would go with an 8 3/4'' seeing that you are starting fresh anyway.
 
Don't forget the torque convertor could be a high stall one and slip a lot and that in combonation with a very high rear gear will cause bad acceleration
 
thanks. I've also been told to look into 3.73 gears. that's what my girlfriends stepdad has in his 350 s10 and it'll get there quick but he stays away from the interstate.
 
I had the same issue when I upgraded cam, headers, carb etc on my car. I picked up an 8 3/4 rear, used clutch type suregrip and some new 3.55 gears.

I rebuilt the rear entirely and shoved it under the car and man what a difference, I still need a converter. That will probably wait until I get my new engine together so I can have one made for my application.
 
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