assembled engine paint removal

I've pulled my engine so I could get to plug to change band apply lever.So I figured I'd freshen up the paint on block and get the headers coated.Most of the paint is flaking off but some of it is stubborn.Using wire wheels but I'm considering acetone for some of the nooks an cranies.Used dupli color to paint it the first time, going to use VHT this time.I cleaned it with purple power,brake clean and paint thinner,in that order, the first time and the paint started peeling after the first year.Don't want to paint over the stubborn stuff for fear of it letting loose at a later time.Want to get all of it off.