I just dropped a used 305 V8 out of a 1987 camero into my boat. There is a lot of smoke and pressure coming from both valve cvrs? The salvage yard ran it before I purchased, with no issues they said. With the pcv's hooked to carb, the plugs turn black and it will barely run. I changed the oil pan, intact manifold and timing chain cvr from the orig. 350 out of the boat to this 305 before install. Did I do something wrong to cause this? Has any one out there had this problem? Help please. Thank you in advance! ALL I own is GM.

 

sounds to me like you have a lot of blow back. if that is what your describing you did nothing. it simply means the motor has seen it's better days. it needs rebuilding. if you wish to get more miles out of it, i would remove the pcv valve and put a blow through cap inplace of it . you don't want to be sucking all that blow back through your carb, intake, and combustion chambers. sick