What is needed to swap out the 4.4 final with the 4.9 final drive thanks

 

a 4.9 final drive, mechanical skills, required tools, and a 6 pack of favorite beer

 

I have the trans apart and the final is in went to put main and countershaft in and the lower gear on the countershaft will not mesh with the final drive gear what am I doing wrong

 

If you are using a 4.929 FD you also need the corresponding countershaft from ATS, if its a JDM transmission you will not need the first gear, but if your transmission is USDM, you will need the distance collar, needle bearings, and the right size 1st gear as well from ATS.

 

Im guessing that its from ATS because the L.S.D that it was attached to is not o.e.m honda This was given to me by a friend that does not know to much about hondas the person that gave it to him said it was all O.E.M is there any distinctive marks to look for to determine for sure that its A.T.S thankyou