1969 Plymouth Fury Slipping

Just picked up a 69 Sport Fu, ry with my 16 year old son. 383 / 704. Original was 2 bbl. Prevvvious owner(s) put on a Road Runner 4 bbl and dual exhaust.

I have 2 major problems to diagnose. I have not worked on a car for 25 + years, In H.S. college, had 66 Belvidere - slant 6 and 2 Fury's - both 318's - 67 Fury III Conv and 68 4 door with 3 on the tree.
1 - Car is blowing black water on start up. Speckles the drive. Is that the carb or possibly the timimg or worse - head gaskets or worst - block. cracked? I have just developed an oil leak - looks like right above the filter around the oil pump. Though it did not burn much more than 1/2 qt on the 800 mile trip home.

2 - Tranny is slipping. On way home, needed to warm up (a few times around the hotel parking lot) before it would shift out of first. Then it was fine. That was last week. Drove it for the first time 2 days ago and it would not shift into reverse. Today, we have revers but no forward drive of any type. Planned on having tranny fluid/filtter done. Fear is a full rebuild. Someone said possibly vaccum. But I do not know where to start there. Vaccum may be the "no heat" problem as well....?

I know this is going to be a project, but the body is straight and fairly clean, interior will be a chore. I just want him to be able to drive it while we work on it over the next couple of years.