just bought my 1990 300zx
 

Thing has problems a knock coming from the rear when I come to a stop not when actually driving or accelerating . and a huge oil leak coming from the rear main motor seal and the front main motor seal. need any good advice on what I should do I'm already in love with the car just need to fix the basics and get it running good so I can actually start building it.

thanks

Kind of sounds like you know what to fix already.