Assembling the new MC/Pushrod, there was no way the retaining spring was going to go into the bore on the MC piston. Piston bore for the rod measured the same between the two MC's. The push rod diameter where the spring goes measured the same as well. Got to looking very closely at the spring and noticed it would not compress to small enough to go in the bore. I noticed the tangs (open end of spring) were resting squarely on the rod, so they would not go any further nor deflect. I bent the tangs in a little more so they would contact the rod at an angle and slip against it when compressed. At this point there was some galling on the bevel on the piston that still might have been keeping the rod from inserting. Swiped it with a little axle grease and it all went together like it was meant to. Never had this issue before. The previous MC just went together like it was supposed to. Burned up some daylight just because of the spring not being bent correctly at the ends. New Raybestos MC36440. Made in China. Quality is just a big word that begins with 'Q' apparently. Hopefully that's the only thing wrong with this part. Now back to routing the new rear line...