Im having some Problems with my transmission and looking for some advice.

The tranny started to pop out of second and eventully stop going into gear completely and found that the syncro was cracked. I ordered the whole third and second assembly with new sycros for MAC.
Installed the new parts and had no luck with them. First time they wouldn't go into gear at all cause the shifter was to tight to move back and forth from first to second. So I filled it down so it would move but now it just slips out of gear with barley any load.

Just wondering where i should buy new parts that will actually work?