Will not shift into 2nd gear when the tranny (700R4 OD) is cold. Once it warms up, the throttle valve doesnt seem to stick anymore. I put some lucas additive in there, and still no dice. The fluid is clean (ive only put 500 miles since the last fluid/filter change). The engine was swapped from the stock 305 to a 350 from a 1969 chevy C10 pickup. The 350 has more than double the output than the measly 165 hp 305. Would this cause stress on the valve body or transmission that was meant for the lower hp engine?

 

likely a broke accumulator spring.