I have heard that having a 28 Sonic with twin big blocks is not good due to the fact that they sit to low in the stern. Does anyone have any information on this theory?

I know that singles are slow. No experience with twins.

I think twin big blocks in any 28' boat is too much stern weight and will cause the boat to be sky happy upon hitting wakes...at least that is my experience. Go either a single 500-600hp motor or twin small blocks such as the Scorpions.