Engine swap - now burning oil/coolant - need help

Guys - I am working on 2 3rd gen Civics (I'd ask the guys in the 3rd gen section, but they never answer). The engine is a d15a2. I drove both cars before we swapped the motors. The 87 4dr burned oil and smoked. But the body is much better, so we took the 86 motor that wasn't burning anything and dropped it into the 87 4dr. Now the 87 is burning oil/coolant. Smells like oil, but it's white. Can't tell which it is. Anyway the only things I changed on this engine are oil pan gasket, timing belt, water pump and valve cover gasket. None of those should cause it to burn anything. The only thing I can think of is that I accidentally put the 87 cat back on (the one that was burning oil originally) back on with the new motor, so now it's having to burn everything out of the cat. The engine won't really stay running in gear either, but not sure if that is related or not. If anybody has any other ideas please let me know. This car is for my little sister and I need to get it running really good for her.

i would say check the cat first if the old motor was burning oil its prolly full of it and blowing it out if it is full it wont want to rev or run worth a sh!t either
hope i helped

Pop the cat off and see if it still does it. By the way "sh!t" makes you look like a dumbass.

if i look like a dumbass then why did u tell him the same thing i did.