I find either the blue ofna 8th offroad box or the 10th/8th box with single 775 motor to be sufficient. The single motor box starts up all kinds of motors. The trick is to make sure before starting the engine is at bottom dead center and also inspect the engine before you fire it up to make sure there are no metal shavings or anything else that can ruin it during the break in process. Also, lube it a little with some ARO or marvel mystery oil and you'd be fine.