Not sure what you mean by "steep angle." I loosen the engine mount bolts to allow the (supported) engine to tilt back as far as possible without damaging the mounts, but that still isn't a very steep angle. (e.g. the oil filler neck shouldn't be hitting the firewall)
Did you use a clutch alignment tool before trying to mate them? It can be very difficult without one, unless you're really good at eyeballing it. SS sells this tool very reasonably.
Because of the starter bulge fouling the tunnel, you'll need to rotate the tranny to be able to slide it straight-on through the pressure plate opening, then rotate very slightly back and forth to get it to mate with the clutch and partially into the pilot bushing, then rotate back again to align the bellhousing bolts. It can fun trying to balance the tranny, pointed slightly upwards and rotated at a 30-degree angle, on a jack and push it home at the same time, but it does work.
Dick Sanders