i put in another 305 tpi and the oil is shooting out of the dipstick..what could be the problem...it did it on the other motor too

 

I have no idea why but it sounds like you have alot of crankcase pressure built up.

 

check your valve seals also could be rings. check spark plugs for oil deposits make sure pcv is not cloged although it doesnt usually make much of a diff if theres enough pressure to blow the dipstick out.

 

Do you have a functioning PCV valve (if you shake it, it should rattle)? Is the opposite side valve cover vented? Does the engine seem to burn oil?

 

i had a 78 monte carlo with lg3 305(even weaker than lg4) that did the same thing, my auto instructor told me he seen it before and what was from excessive crankcase pressure due to extreme blow-by of the rings, and that he has never seen any engine with that much blow-by last more than a month. 2-days after diagnosing my 78 the engine threw a rod out the side of the block.

 

the pcv valve is new, and the motor doesnt burn oil, the opposite side is hooked up to the throttle body

 

After my first re-build, I had the same problem when I got on it. It really sucked cause the oil would spill onto my exhaust and smoke like crazy! Turned out the land area of the #4 piston was cracked which caused blowby and excessive crankcase press.