Hello i have an 86 t/a with the original 305 TPI (94,000 miles) and brand new auto-transmission 2500 stall. I took the motor out to put in the transmission just cleaned the engine and painted it. It did this problem prior to the new transmission. The problem is when it shifts to second the engine bogs down and makes a rattling noise and goes away if i give it more gas. Another problem that happens is when i am driving sometimes i press the gas and the engine makes a weird cherping noise like metal on metal and a weird smell comes from the exhaust. Also when i rev the engine in park ( almost red line) the engine runs smooth with no rattles or anything. I need help its really pissing me off.

Thank you