I would think that they should respond to pressure the same. Did you rebuild them at the same time? I believe you probably did. I agree it is strange that all intakes didn't leak down and all exhaust did. I'm not an expert by no means but I would submerge the exhaust lifters under oil and see if you can get them to pump back up. I didn't have very good luck with my lifter rebuild and ended up replace all of the lifters with ITM lifters for around $350 IIRC. Maybe one of the forum experts will chime in shortly