280z throwing smoke

hello names chris, i have a 76 280z I recently did a trany swap from auto to manual about a month ago. Now my problem is my car is smoking its white grayish smoke.The car has been sitting for about 6 months slowly working on it I finally got the trany in I started my car and the rpms were high at the cold start i tried to lower it but nothing worked . but after it warms up the idle goes down to 9rpm. I have check my plugs no oil on them, my coolant has no signs of oil either. but i did notice oil under my throttle body? can that be whats causing my car to smoke? I have also read that when a automatic trany gives out some fluid can be suck into the manifold so maybe that would also be whats causing the white smoke?

thanks for the help