I have a 68 327 RS

The last guy had an aftermarket chrome fill tube on the car that leaks all over the place after driving. I have the original stock tube and o-ring I want to put back on.

I had to cut the chrome tube out since i was losing patience getting the thing out. I'm having an equally difficult time getting the stock tube back in. Is there a trick to this? Does something need to be removed for more clearance?

Does it go in from the top or bottom?

I'm sure someone here has done this before and can shed some light on this for me. Thanks in advance for any help.

The tube goes in from the top.
Lube the rubber seal, whether an O-ring(1st design) or a cone shaped(2nd design) with ATF.
From above, slowly and firmly push tube into trans hole until seated.
Remove the one bellhousing bolt and attach bracket to hold tube in place.
Done.

Thanks, I'll give it a shot.