One thing I learned was to try different sized tires on your vehicle to find out what ratio you would prefer. If it's sluggish with the tires you want, lower profile tires will feel like a lower gear ratio. With a calculator (like the one on 4lo.com I use) you can figure what the equivalent ratio is and reverse engineer it to the nearest ratio you like. From: "Armand Eshleman" To: "AMC, Rambler, Nash, Jeep and family" Subject: Re: [AMC-list] engine rpm versus mph Message-ID: Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original ----- Original Message ----- From: "Joe Fulton" To: "AMC, Rambler, Nash, Jeep and family" Sent: Tuesday, April 12, 2011 10:33 AM Subject: Re: [AMC-list] engine rpm versus mph Another thought? In addition to the "bouncy" tach, are you really doing 70 mph? Do you have the correct speedo gears? Have you run a measured mile to check? Joe Fulton I know I have the wrong speedo gear, but, yes I have done the measured mile thing and compared side by side speeds with a known accurate car. The speedo is off about 5 mph, so I allow for that variation when descibing the tach reading 2100 at 70 (speedo reading 65). Heck, I guess I should be more thankful the tach works at all ! it is 41 yrs old after all, and never been apart. Armand added note, I have conversed with the people at Tremec about speedo gears and they've said they can calculate the correct gear needed if I give them the varibles, tire diameter, final drive ratio etc. good to know when I get it decided which final ratio will go into the AMC20 axle -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://list.amc-list.com/pipermail/amc-list-amc-list.com/attachments/20110413/19889e61/attachment.htm> _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com