I was in the process of changing my motor mounts when I noticed that it looks like the rubber mounts are riveted on to the brackets that connect to the motor. Would I have to drill out these old pins and connect them back together with bolts the the new ones? The pictures I used are from the internet since mine are still in the car, I bought the rubber mount like in the 2nd picture.
Let me start off by saying I have never messed with inline sixes. The new mounts ought to be a bolt-in affair and should come as a whole assembly like in the second picture. I take it that you haven't rec'd them yet? The rubber is bonded to metal plate. I would bet rivets were insurance back in the day, when the manufacturing/adhesives may not have been as good. If the new mount looks that different than the original, I am betting it is an improved design. The important thing to look at would be the relationships of where it bolts to the block and where it will bolt up to the frame mount. Keep in mind, an old one can be a bit squashed from use, too. Someone who plays with inlines can probably tell you more.
I’ve never seen them riveted together like that. Mine were bolted together from the factory (car had 19,000 original miles on it). If you are using Anchor lower motor mounts, be careful tightening the nut on the bottom. The studs on the rubber mount will break easily... ask me how I know. Looking at YOUR picture, I’d say you will have to drill those rivets out.
Paul's picture reinforces the idea that I have never played with inline sixes. I think if you would have originally included one more pic of your old one, I wouldn't have commented. I'm used to slapping the mounts on a V8 and dropping it on the frame stands. These six mounts do look more involved than I am used to, looks odd to me.
I received them but I'm not home for the next week or so and forgot to take pictures of everything before I left, but they did have a plate on the new rubber mount. Maybe the later years used rivets instead of bolts? It just really confused me when I was about to pull it out and saw I couldn't actually separate them from the brackets. I guess I'll just drill them out and bolt them back together if that's what other mounts look like! I'll post a picture of mine when I go back home.