I think most AMC cars came from the factory with restrictive exhaust systems. Opening up the exhaust system is one of the best things you can do to increase mileage. My 1971 Gremlin picked up two miles to the gallon when I installed Clifford headers. I was already running a Thrush muffler with less restriction than the factory muffler. The AMC people built good cars but sometimes they didn't think right. They probably went with the smaller exhaust systems to save a few pennies or dollars but by increasing the size of the pipes just a little they could have increased mileage and had that to brag about. As far as the six cylinder engines in the larger cars I don't think they helped mileage much since they had to work harder with the heavier car. When the Pacers came out I drove one to see how it rode and performed, it was a nice car but sluggish. My Gremlin had lots more acceleration, and that was before any major modifications. The Pacer should have never been built with the six-cylinder engine, it should have had the 304 V-8 from the start after the Wankel engine was cancelled. This was just another bad corporate decision. I know they were struggling with gas mileage but I doubt the 258 gave any better mileage in the heavier car than the 304 would have with the right gears. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.amc-list.com/pipermail/amc-list/attachments/20070619/1ec110de/attachment.htm _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list