Thanks for the warning. The concern I have now is that by beefing up the inside and changing the ratio's I will put more stress on the case its self as it will have to break both tires loose in order to release the stress. Given I don't hot rod around everywhere but like to get into the peddle a time or two whenever I do take it out, would this case be able to handle the power my engine is producing?

 

your totally fine as long as you are runnning street tires. If you put drag slicks on you may run into a problem.
I am sure there was plenty of drag racing going on with these rear ends long ago. just because it is not the newer ribbed casing does not mean that it is week. I would think that you would break a stock u joint before you would crack the case. but that is just an opinion.

 

^^^ Agree. Also not sure if I missed it or not, is the car an AT or MT? If your running an AT you should be fine. I have had the 3.55's in my car for 14 years and besides a little street racing have not had any problems with it.(Yet!)

 

I broke an old style case, with less than 300 hp, a 3.25 tracloc, toploader and sticky Yokohama ES100s. Launching with a stick can be pretty violent. If you look at the pictures you can see that there is a lot more meat below the pinion bearing in the improved case. Plus they added the vertical ribs. Ford improved them because they were breaking, 2+2 and some of the oldsters around here can tell you that many an eight inch crapped the bed back in the day. First it was the tapered axles then it was the cases. If you're not going to get on it or have skinny tires you'll be fine, otherwise I suggest at least getting an improved case. There's plenty of them out there.

 

Well I went ahead and ordered the complete 3rd member from the e-bay link. I called the guy and he was real cool. He thought it would be fine for my application, though he may be a little partial to getting a sale, and he builds them for a living.

I don't plan on putting anything other than street tires on the car and it is an AT trans, so I am fairly comfortable that it will hold up fine from what you guys have been saying. Plus I am keeping my old 3rd member so I will have a backup just in case I do break the one I am getting.

Thanks for the input, advice, and warnings.

 

I was under the impression you had a stick, where I got that idea I dunno...
You should be fine with an automatic.

 

sweet man... glad you bought it. I still want to upgrade mine. Currently my 3rd has a mini spool in it and I desperately need it gone but I need to loosen my grip on $5-800. Would love to just keep my ribbed case and find someone to posi it up for me but I am having a problem finding quality 8" posi units and gears for the 8". Any suggestions when just looking for the parts???

 

The only thing I found on the lines of any kind of selection was at Summit Racing... Not sure about quality though.

 

Everything I have found for the actual posi is around 460-580, then add gears... 180 or so, seals/bearings etc 50? How are these ebay sellers making money at 800 or less built and for sale? Granted I am sure the parts price I see have a 25-30% mark up from the seller which is what a builder is doing too... Plus for 800 or so the ebayer is including the case. Doesn't add up...

 

Well I guess you were right... my expensive $670 lesson is don't trust that guy. I ordered the 3rd member from him Jan 19th and have yet to receive it. I have had limited contact with the man and he keeps pushing it back to the point I am positive he has no intention of sending me anything. Initially it was 1 to 2 weeks before he shipped it, then 3 to 4 and now he isn't even talking to me. I have sent him one final e-mail stating that if I do not receive the 3rd member by the 3rd (43 days since the purchase) of march I will dispute the transaction with PayPal. PayPal only allows disputes up to 45 days after the transaction. I just thought you would all like to know. Beware of the guy and any of his products.