Differences Between Mack B-73, B-75 and B-77

[CaptainCrutch 270]

I really love these models of trucks because they have the B fenders I love with a huge radiator and the option of an L cab that I also adore. I’m just wondering what the difference is between the B-73, B-75 and B-77. I plan on trying to buy one at some point in the future to haul my antique firetrucks with I just can’t at the moment.

[yarnall 919]

A B73 has Cummins power. A B75 has Mack power.  I don’t know what a B77 has but someone else will. The L Model style cab was an option. They could also have the standard B cab. 

[j hancock 11,761]

Over the model run there was some variation in some specs, but this is a basic look.

B73 -  Cummins NH 220 and NH 250 HP 

B733 - Cummins NT 250-280 HP  turbo motors

B75 - Mack END 673 170-180 HP, also END 711 after 1962

B753 - Mack ENDT673 205-210 HP turbo motor

B755 - Mack END 864 250 HP V8 motor

B77 - Supercharged Cummins NHRS

B773 - Cummins 335 HP turbo motor

[41chevy 9,800]

Wasn't Waylon Jennings Mack a B77?

[CaptainCrutch 270]

Thanks everyone, I’m a Mack man all the way so it looks like I’ll be looking into getting a Mack B-75, B-753 or a B-755 when the time comes. I have the 2 fire trucks but I want one of those B-75s to be my first real semi truck. Once you go Mack you never go back...

Edited January 19 by CaptainCrutch

[Freightrain 2,289]

But there is something about those old supercharged Cummins.  They do sound GOOD!!!

 

Edited January 19 by Freightrain

[Maddog13407 2,114]

ialways thought Miss Jesse started out as a B75 and Waylon had a shop make it a B77 or B773, somewhere I have read a story of the Diesel shop he used back in the day for his fleet. he also had an F model and I have seen pictures of a cabover KW

[BillyT 543]

Did Waylon have a tractor named"Amanda" or would Jesse have been jealous?

[mackdaddy 840]

On ‎1‎/‎18‎/‎2019 at 5:59 PM, j hancock said:

Over the model run there was some variation in some specs, but this is a basic look.

B73 -  Cummins NH 220 and NH 250 HP 

B733 - Cummins NT 250-280 HP  turbo motors

B75 - Mack END 673 170-180 HP, also END 711 after 1962

B753 - Mack ENDT673 205-210 HP turbo motor

B755 - Mack END 864 250 HP V8 motor

B77 - Supercharged Cummins NHRS

B773 - Cummins 335 HP turbo motor

what about the B-7553........or an 864 twin turbo?

[Superdog 5,880]

21 hours ago, mackdaddy said:

what about the B-7553........or an 864 twin turbo?

never made one as far as they records go anyway.

 

[AZB755V8 473]

17 hours ago, Superdog said:

never made one as far as they records go anyway.

 

Mack did not make a turbo V8 in a B model from the factory that I know of. I did see a 864 twin turbo B model for sale in the Wheels of Time years ago, it was yellow, wonder what happened to it? Think they were asking about $20-25K for it.

This is my 1965 B-755 that came with a normally aspirated 864. They were not good engines and forget about parts so when the truck was restored I put in a rebuilt 375HP 866 V8 single turbo that I could get parts for back then. So there are at least 2 B's with Turbo V8's around. I really wanted to put a E9-500 in but the Quadbox still in the truck would not have survived for long. Engine color is right for 1965 V8 but originally a Silver engine.

[terry 382]

very very nice.👍👍👍  terry

[Brian L Blaylock 13]

I have a ENDT-865 shoe horned into my B-615

[AZB755V8 473]

11 hours ago, Brian L Blaylock said:

I have a ENDT-865 shoe horned into my B-615

The truck should have had everything needed to fit the newer 865 into it. The B-615 did have an 864 in it and there were modifications right from Mack to get the V8 to fit when built. It would be hard to fit a V8 into an original NON-V8 B-model because of it. We did nave to modify the pulley in back of the fan to get the 866 to fit in the B-755 to length reasons, it is certainly a tight fit and even tighter in a B-615.

Cool truck....But we have to have photos as proof it exist... Photos Brian Photos... 

[h67st 812]

22 hours ago, AZB755V8 said:

Mack did not make a turbo V8 in a B model from the factory that I know of. I did see a 864 twin turbo B model for sale in the Wheels of Time years ago, it was yellow, wonder what happened to it? Think they were asking about $20-25K for it.

This is my 1965 B-755 that came with a normally aspirated 864. They were not good engines and forget about parts so when the truck was restored I put in a rebuilt 375HP 866 V8 single turbo that I could get parts for back then. So there are at least 2 B's with Turbo V8's around. I really wanted to put a E9-500 in but the Quadbox still in the truck would not have survived for long. Engine color is right for 1965 V8 but originally a Silver engine.

 

AZB, those polished aluminum pieces on your engine look great. When my truck grows up, I want the engine to look just like yours!

[AZB755V8 473]

2 hours ago, h67st said:

AZB, those polished aluminum pieces on your engine look great. When my truck grows up, I want the engine to look just like yours!

Thanks, The polished stuff would not have look as good on a silver engine that it started out as. 866 V-8's where silver in the early 70's and that is what I started with. Gold color was on the 865's

All it takes is time here and there, files, sandpaper, polish and a BLACK hands from aluminum grit and polish. It did not happen over night but over a year or two. Man the casting to start with are not good quality, you can see definite differences in color within a valve covers and radiator. Must have been the filler scrap aluminum they melted into the mix when cast. 

[Rob 1,427]

I had some small pieces parts for an ENDT-866 powder coated aluminum finish and they look very close to polished aluminum parts, but they'll stay looking like that without maintenance. I may do the rocker covers and intake plenums too, but haven't looked into the cost yet.

[Truck Shop 1,141]

 That Pete has a Iron lung on it.

On 1/18/2019 at 9:36 PM, Freightrain said:

But there is something about those old supercharged Cummins.  They do sound GOOD!!!

 

 

Edited January 23 by Truck Shop

[Truck Shop 1,141]

That Pete has a 300 Iron lung

[AZB755V8 473]

36 minutes ago, Truck Shop said:

 That Pete has a Iron lung on it.

 

 

 

 

34 minutes ago, Truck Shop said:

That Pete has a 300 Iron lung

Just observing but did this post to the wrong thread? We are taking about B-7X Mack's here not Pete's? Is this related to a Supercharged HNRS in a B-77 Mack? By the way this engine is my second favorite behind an E9, so much so I got one in a 53 LTL. No disrespect.

[Freightrain 2,289]

Yup,. I like the sound from them.

The Pete came up because I commented about liking the sound of the old Cummins and I found that video to let everyone hear it..  I like Mack's, but also the old supercharged Cummins.  That's all.

Edited January 23 by Freightrain

[Brian L Blaylock 13]

AZB I’ll see what I can do 

[mackdaddy 840]

On ‎1‎/‎20‎/‎2019 at 5:42 PM, Superdog said:

never made one as far as they records go anyway.

 

I don't think Mack ever designated the V8 B series with a 3 for turbo. Here is one that was at Lexington that had the factory installed twin turbo'd V8.

 

 

[Superdog 5,880]

22 hours ago, mackdaddy said:

I don't think Mack ever designated the V8 B series with a 3 for turbo. Here is one that was at Lexington that had the factory installed twin turbo'd V8.

 

 

did they have the twin turbo V8 in '63? I thought it came later,'66 or so.. Maybe this was a test truck for the engine??

[AZB755V8 473]

That Gray B with the twin turbo 864 maybe the truck that I was talking about for sale years ago and was yellow back then if I remember right. Yes that twin turbo V8 may have been factory installed just in another truck first. Then transplanted like the one I got. The 866 was factory installed in a R model before it was installed in my B-755. Originally a V8 truck just had the normal 864 at birth. No slam here, just happy to see one exist, factory or not!! Rare, Rare to see an 864 running let alone a twin turbo, Great looking B!!

By the way if anyone wants a set of those 864 turbos in good shape for spares or to use let me know $500 plus the ride. Got base and pedestal to throw in too.

Looking at the photo, that owner must keep a close look at the stacks with TWIN smoke mirrors. Maybe one stack is different from the other. LOL!!