Jump to content

Recommended Posts

I have a chance to buy a freightliner air ride rear with 3.90 gears will this be geared to high for my b model? I am putting a 260 hp. 675 in and keeping the tr 70 duplex. Any thoughts? thank you

Share this post


Link to post
Share on other sites

If your trans is a TRD72 and you use 3.90 rears - top speed will be around 62-64 mph. Is that fast enough to suit you? I have a 675 engine in the old "draggin wagon" with 10 speed  (direct in 10th) and a 3 speed Aux behind it (0.84 in OD) with 4.00 rear on tall rubber which gives 3.36 final drive ratio - top speed is 80 mph against the governor. I would love to have a double overdrive - 0.69. That would give 2.76  final drive ration but that would require an airplane radio!!!!!!!!!!!!

Share this post


Link to post
Share on other sites

still wondering where your getting endt675, 260 hp ,237 hp motor.....more info needed the tr72 series came in single overdrive and double 9 speed, 10 speed,10 speed overgear, 13 speed double over, 15 speed single over, 18 speed double over, 20 speed single over, 20 speed direct...

Edited by Maddog13407
  • Like 1

Share this post


Link to post
Share on other sites

I just bought the engine it was in a 1980 fire truck I was told it had low miles. I was looking at a 285 hp. 676 but it had water in the pan and it turned slow like it had rust in the cylinders and the owner of the junkyard wouldn't sell me the engine so we settled on this one.We settled on a deal for the engine and an air ride freightliner rear axle and 2 hub pilot high tread tires and 2 aluminum rims with good tires that should keep me busy in the shop most of the winter. My truck  says b42 on the hood but it had the early 673 and the tr72 I figure it is just a straight 10 speed the way it shifts. I guess the truck has been altered. Dave the owner of the yard says all the mack stuff gets shipped to Africa. Summit core is the name of the yard in springville pa. I have been buying small stuff from him for 4 years and he has been fair on his prices.

Share this post


Link to post
Share on other sites

Just found your post.    I have 4:30 rear, direct drive duplex, tired non turbo 673, and tall drive tires (12r 22.5).     It runs 66 mph at 2300rpm.   Ok bobtailing pretty sleepy with any kind of load.     

Share this post


Link to post
Share on other sites

Hobert 62 I am just sliding a 3.90 rear under my truck air ride and with the 260 hp. engine it should do the speed limit on the highway I also have a direct duplex

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...