CrankCase Pressure SPN 101 FMI 15 FC 1974

[Waterloo]

EGR Tuneup, replace the sensors, Intake manifold and Exhaust back pressure sensor. Go from there, odds are you need the in frame. And do NOT just take it anywhere! Been there, and done that... Not many shops in the USA that rebuild these motors do it properly, maybe one or two. Mr Hagg is a trusted shop, no clue who the other shop is. For what it is worth, unless you do it yourself, and have the tools to machine the block and set the liners properly.