mustang430

i just recently got my car all back together and im slowly working the bugs out of it. I put in a new clutch, flywheel, driveshaft, and shifter along with some other things, but now its alot tougher to shift than before. Just slowly driving in 1st then slowly go to 2nd its really tough. What would cause this? I also changed the tranny fluid out for RP synchromax. It only takes 3 of them bottles right? maybe im just low on fluid?

Whamo

define "really tough" you should be able to quickly pull it from first to second in under a couple of seconds without too much strain.
it also could be the short throw shifter, the shorter the shift the harder it is.