changing ratio of the rear differential

may require main case take apart. unless there is separate cover for ring and pinion?

take some pics and post.

found this but i dont get it can you please explain
"The rear differential requires that the LSD carrier and bearing plates from your SVX rear diff be swapped into the 4.44 rear diff. This requires some modification to the rear differential housing with a grinder to make room for the LSD carrier"

what about this? By switching to the 4.44 gear ratio, you increase torque to the wheels by over 40% in first gear down to over 10% in 4th and the car becomes much livlier and easier to drive in hilly and city areas. The MPG also increases slightly due to less throttle being needed to actually move the car from a stop and keep it moving. It will also drop your 0-60 times by around 1 second and lower your 1/4 mile times by about .5 seconds. The 4.44 transmissions also have all the issues that were wrong with the original SVX unit fixed and they live a FAR longer trouble free life due to it. They also produce less heat because they do not have to work nearly as hard due to the lower gear ratio. It is undoubtly one of the best bang for the buck mods available for the SVX and is becoming the common thing to use when the stock 3.545 geared unit eventually and commonly blows up, due to the far lower cost and better availability of 4.44 vs.stock.

it's saying 444 is superior in everyway? so why not just use it as is?

sorry, i see that in order to use the other trans (444) you have to do the bearing/carrier swap. probably axle shaft difference. too bad the fella dont show ya how it's done.

maybe you could contact him and ask for instructions? he seems like he would help.