Listen Eric before you go on heavy fix use liqui moly flush and add thick oil use 15w40 even 15w50 can be used according to Mexico owner manual it's kinda old engine old is gold . Anyway after flushing use thicker oil . The tensioner is overated problem you will be fine doing the upper tensioner it's very easy get the parts from rock auto ebay and autohauzs avoid the hypocrite Christopher he rebadge ebay parts as it's ford original parts . Anyway probably after the flush and new oil the pressure maybe become fine get copper denso spark plugs the iridum is very overrated
get valve cover gasket get mahle use additive fuel and engine. The transmission probably low fluid add on its not that difficult if it's dying then use Lucas transmission fix it works wonders my transmission was dying but now thankfully it's working better than before