8-1/4 rear end

[busteed]

Everyone is telling me to get a 8-3/4 rear end for my 74 charger.  The only problem is finding one.  I currently have a 8-1/4 underneath.  How much $$$$ am I looking at, making the car posi with 3.91 gear ratio?  What would be your suggestions for someone on a budget wanting something like I am after? 
                                       BUSTEED

[is_it_EVER_done?]

Though I may be 100% wrong on this since I have never looked into it, I doubt that either a posi, or low gears are available for the 8-1/4.

Even if they are, an 8-3/4 will be infinitely stronger, and far cheaper to obtain what you want.

[doctorpimp]

Though I may be 100% wrong on this since I have never looked into it, I doubt that either a posi, or low gears are available for the 8-1/4.

Even if they are, an 8-3/4 will be infinitely stronger, and far cheaper to obtain what you want.

You can get a Sure Grip unit for an 8 1/4 and I'm sure you can get 3.91's too, but EVER is right...it'll cost you just as much as going with the stronger 8 3/4.
Keep looking, you'll find one...
Where are you located?
Maybe posting in the Parts Wanted section will get you one close to you...

[71charger_fan]

If you're not making a lot of horsepower you may not need an 8.75. I've seen Dakotas at the track running in the 13s with 8.25s. 8.25s are common in Jeeps and any 4x4 catalog will have plenty of vendors selling posi units and lockers for it. The Ford 8.8 unit is becoming increasingly popular in off-roading and it's pretty common, not to mention a lot cheaper than a 9 inch. Unless you're drag racing it, your 8.25 should last a very long time, even with a warmed up engine. But look around, putting a lot of money into an 8.25 doesn't make a lot of sense if there's an 8.75 to be had.