Freightrain

I was going to try to add one to my 237, but got a whole motor. I hear they are quiet noisy at full song? Guess I will find out. Seeing they are 40+ yrs old, it is likely harder to find one? Mine does work, as I had motor running and if I jabbed the throttle it would send a touch of wind into it and it would spin easily. They were popular before CAC was mounted in front of radiator.

The difference is, the 237 and 285 were made for only 5 gears. The 300+ isn't, so I bet it was slow to recover on a shift.

That Mack 10 spd must have similar OD as my Triplex. I want more though. A quiet, get home gear. Even if I only used OD on level or downhill. Not sure a 12 spd would fit under the cab in a B model? I would love to have one.

That would be a cool set up. Seen a few for sale but a bit pricey and not sure about rebuilding cost? Availability?

My 300+ has the flip flop linkage going to the pump so it can push instead of pull. A new local FB friend pulls using a 285/300 and removes the intercooler in an R model. Apparently this pump is " the pump" to run . He turns it like 3000+ rpm, all stock bottom end. Says it is no problem.

The 300+ needs more gearing. Like a Thermodyne. The truck had a 5 spd, but I bet it was a real PITA around town. But it was a fleet truck, so I assume that is why they used a 5 spd.

I'm not overly worried about a deep low. Like my deep under 6041 just for the slow truck race. Beyond that I don't "need" it. I know I am dealing odd pieces and trying to get something that works well together. Decent splits and something like the double OD I have using my Triplex and 6041. Gets me 65 mph at 1500ish. Much quieter then 1800! I don't like lugging it much with that 6041 and the 300 will be harder on it. I wouldn't kick a 18 to the curb if I found one reasonable, even it it means paying full core for it? If there is a DO version that would be a plus. I have the Eaton chart saved, need to look around. I need at least a single OD, period. I will remove the 6041no matter. As for clutch housing, Geoff and I were already poking around at those before I rebuilt the Triplex. Using the Triplex? I could, but I don't want to have to "baby it". If I feel the need to let it rip, I want a transmission that will not flinch. Just a note, I purchased a new $10k transmission for my race car. It is the top of the line, badass, never have to worry kind of transmission. I have no problem with doing that for the Mack. I only want to do this once. Thanks for all the input guys. It will come together somehow.

I want to cruise at 14-1500 rpm @ 65 mph. Not 1800 I am now. Those 3.55s or a double OD like I basically have using that 6041 box. I'm not worried about going fast, just fast enough without all the noise.

My initial thought is NO. Everyone says to but I don't want to worry about something going wrong. These transmissions arent on every block anymore. My next thought is get rid of the 4.10s for a set of 3.55s if I can find a set for a Rockwell. Then I can run a 13 spd. If changing rear gears becomes a hassle, I want a true double over 13. Not a homemade version. I want more road speed at lower rpm(noise level). I will be removing the little 6041 box I have hanging in there. Much to fragile.(I'm a gearhead, I want something I don't have to drive like I have an egg under my foot). I had thought of using the 5 spd that came with engine and find a 1241 and use it for splits, plus if I get a 1241C it has deep under like my 6041. Lots of "maybes" and "ifs".

The 237 is a huge upgrade from the 673. Can't wait to see it with new motor! I found out last winter that my throttle was not quite wide open at WOT. I adjusted the arm just a touch and WOW what a difference. It really pulls the hills now. It was good but that last little touch of fuel made a big difference in keeping speed with my trailer on steeper hills. Always had to drop a gear, now I can almost not have to. Can't imagine another 100hp?

Ok, it makes sense. It uses an adjustable rocker cup to apply extra lift to open the valve instead of a Jake housing. Normal setting it has lash, once pressure applies it pushes rocker further opening the valve. Kinda ingenious actually.

I've run valves, so I understand the procedure. On my hot rods, I always do one cyl at a time. They have cheat sheets on how to do multiple cylinders at a time but I never do it that way. Ever. Even after getting grief for it. "Oh, you're taking too long". Whatever. This having so much lash surprised me. Why does it require so much for a "dynatard" cam? What is special about it? I'm just glad it isn't a cam lobe problem. I did the valves on my 237 and the Jakes without issues. I know Jakes are different but I followed the sequence and they work fine. I want to transfer the Jakes over to this engine, if possible.

Will do. Not my first motor rodeo. Been doing hot rod stuff for nearly 40 yrs.

I have the three pieces but they are all assembled and no easy way to measure the ball size.

Have to wait to get engine on legs, as it is just sitting on a few pieces of wood. Any big bar will have it laying on its side, on the floor! 😨 I remember the 673 was like 150#? when I replaced a few broke studs years back. At least that is what I pulled it to because that was all my torque wrench would go.