[z2815]

does any body know what chevy 400's are external balance and witch are internal balance. also what cars came with 400's in then from 70-80. i have a 400 in my camaro and it has a baddddddd vibration i think it's the flexplate but i don't know if it's internal are externaly balanced. the problem is it's my driver in the winter and i don't feel like pulling the pan to see. any help would be very nice because this is driving me crazy.