Bumsteer Posted 2 hours ago Share Posted 2 hours ago I am looking at an R model to buy with a 673A engine, 315 hp, RTO12513 trans, Rockwell single axle 4.33 with a tag. Any one have any idea what highway speed this would run? Also any feed back on the 673 engine? I am not a mack guy just want this for a toy hauler. It doesn't have power steering but i would assume since it is an r model wouldn't be hard to add. Quote Link to comment https://www.bigmacktrucks.com/topic/76453-what-kind-of-speed-from-this-combination/ Share on other sites More sharing options...
Mark T Posted 1 hour ago Share Posted 1 hour ago around 70 @2000 RPMs give or take depending on the rubber and where it's governed at Quote Link to comment https://www.bigmacktrucks.com/topic/76453-what-kind-of-speed-from-this-combination/#findComment-592274 Share on other sites More sharing options...
Geoff Weeks Posted 1 hour ago Share Posted 1 hour ago I come up with 67 MPH @ 2100 rpm with 11R22.5 rubber. If your tires are different, then the top speed will be also. Quote Link to comment https://www.bigmacktrucks.com/topic/76453-what-kind-of-speed-from-this-combination/#findComment-592277 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.