Background: I have two 97s and Joey’s turbo is going on my favorite one of the two. But, very low compression in that engine (350k miles with orig HG) and much better in the other (160-170 on all with 385k but has had HG replaced). I’m stumped because I was trying to figure out if just a head job on my lower compression engine would do the trick instead of swapping the two eng/trans/transfer and avoiding a full rebuild (expense). Used a vacuum gauge off of brake booster port. Was hoping with a jab of the gas that tired engine would drop to 0 and then to 20 and settle at 20 (indicating worn rings) and the better compression one would drop to 0 and snap back to 24/25 then settle at 20. But, both perform identically - drop to 0 and then to 23 or 25 (depending kn how sharp the snap is) and settle at 20. So, is my thinking correct that a head rebuild and new gasket is likely to bring good compression back to the lower compression engine since it appears the rings aren’t worn out? Thanks in advance.