Oldnewbie,
The correct tracks for an Early production E8 Sherman would be the T-66 dry pin tracks. Later during the war the T-80 all steel chevron tracks were introduced. I am currently working on the Tasca E8 kit tracks myself. They are tricky to put together as well as being able to remain workable. I feel plastic tracks are as good as you will get in my opinion. A few years ago a company by the name of Armor Track Model Co. offered plastick indy link track. These were THE Best on the market. Sadly they have been taken over by Trumpeter and as I have been told the plastic used to mold the sets is of a much softer variety making assembly difficult. Fruil tracks while cast very nicely I feel they put too much weight on the Idler wheels, Drive sprockets and support rollers causing them to toe out a bit.
Try the kit tracks again. Once you have a few links made up it goes quickly.
Best wishes!
Frank Blanton