I bought this awesome wagon for $1k w/ only 81k miles on it but after several long road trips the engine finally gave me some trouble...the belt connected to the radiator fan snapped and knocked the water pump loose, which in turn knocked a hole in the radiator & caused antifreeze to spray all over the underside of the hood...a mechanic checked it out & thinks there might be damage to the head gasket on top of those...i'm trying to figure out if it's a better move for me to replace the original parts of the engine or if replacing the entire engine altogether would be smarter? and if so what type/size engine would be best for this body type that'll still have the great gas mileage that the Z20E gets?