Hello! So I’ve been working on my recent acquisition, a 1968 Valiant. It originally came with a 170 slant six engine and a three speed manual column shifted transmission. At some point, somebody put a 225 engine in the car. It has a shake at idle and a harmonic vibration at cruise speed. Looks like they reused the 170 valve cover, intake and exhaust assembly, oil pan and what looks to be the harmonic balancer. I only say that because all of the 170 parts are red and the block and head are black. I don’t know what year the 225 is, it has no identification stampings on it anywhere. It just has a casting number on the drivers side of the block that says 030–11. Question is, does the 170 and 225 use a different harmonic balancer??? Also, could the flywheel be incorrect as well? I know the 170 and 225 have a different register hole on the flywheel, but is the balance different? Any help is appreciated!