Craig N Posted October 29, 2022 Share Posted October 29, 2022 So I’m picking up a nice B 42 in a week or so, with any luck. Body is great, but the motor (673 NA) is locked from sitting for about 4 years. The plan is to pull the injectors, put some marvel mystery oil in the cylinders and let it sit for a few days/week. I’ll Jack up the rear, put the duplex in high gear and hopefully rock the wheels back and forth to get her unstuck. I’m going to try doing this rather than try pulling it on the road. That said, if I can’t find another 673 somewhat local to me for a reasonable price, I have a Cummins 350 (which is also probably locked) that I have access to. It’s basically brand new. I could tare the heads off of it and try unlocking it and see what happens. So, will a Cummins 350 fit in a B42 chassis? What are my twin stick transmission options for that motor? I’m assuming I’ll need new motor/transmission mounts to start with. Great forum here. Thanks for all the help and information. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/ Share on other sites More sharing options...
tjc transport Posted October 29, 2022 Share Posted October 29, 2022 that is a big engine. a better fit would be a 6BT. they can easily make 350 hp with very little money. 1 1 Quote when you are up to your armpits in alligators, it is hard to remember you only came in to drain the swamp.. Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514004 Share on other sites More sharing options...
70mackMB Posted October 30, 2022 Share Posted October 30, 2022 Welcome Craig, Welcome to BMT and your off to a good start! Interesting post with a picture the first time. lol .....Hippy Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514013 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 7 hours ago, tjc transport said: that is a big engine. a better fit would be a 6BT. they can easily make 350 hp with very little money. I do like the 6bt’s, I have one in a 2001 dodge. I would probably go with a Mack 237 or 285 before I did that though. Would like to bolt a twin box back up to it. Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514015 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 1 hour ago, 70mackMB said: Welcome Craig, Welcome to BMT and your off to a good start! Interesting post with a picture the first time. lol .....Hippy Glad to be here!! Cool pic, right? I should have better ones of it tomorrow. Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514016 Share on other sites More sharing options...
davehummell Posted October 30, 2022 Share Posted October 30, 2022 Get a 675 it fits without too much hassle use your flywheel and front balancer and water pump I did it and it was a piece of cake. Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514018 Share on other sites More sharing options...
Onyx610 Posted October 30, 2022 Share Posted October 30, 2022 Cummins ISL 8.9 Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514019 Share on other sites More sharing options...
Onyx610 Posted October 30, 2022 Share Posted October 30, 2022 Or Cummins ISC 8.3 Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514020 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 19 hours ago, davehummell said: Get a 675 it fits without too much hassle use your flywheel and front balancer and water pump I did it and it was a piece of cake. Oh nice, that’s probably the way to go. I think the transmission will bolt right up too. From what I’ve read, the 675/237 has way more torque and can blow the transmission easy if you aren’t careful. I won’t be hauling anything with it anyway, just gonna be a cruiser. Hopefully I can get the 673 running anyway. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514060 Share on other sites More sharing options...
Mean Green Posted October 30, 2022 Share Posted October 30, 2022 I like the bumper its diffent than a flat one truck looks to be in good shape I also have a b42 was the rear in yours changed to a diesel rear or are they still running a gas rear the ratios are way diffrent in them Quote If your going to be a bear be a grizzly Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514063 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 1 minute ago, Mean Green said: I like the bumper its diffent than a flat one truck looks to be in good shape I also have a b42 was the rear in yours changed to a diesel rear or are they still running a gas rear the ratios are way diffrent in them That’s a good question, I have no idea. How would I tell? Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514064 Share on other sites More sharing options...
h67st Posted October 30, 2022 Share Posted October 30, 2022 3 minutes ago, Craig N said: That’s a good question, I have no idea. How would I tell? Jack one rear wheel up and spin one revolution, count how many times the driveshaft spins and divide by two (such as 9 driveshaft revs would be a 4.50 diff ratio). Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514065 Share on other sites More sharing options...
Mean Green Posted October 30, 2022 Share Posted October 30, 2022 is yours a single axle or tandum mine was a single axle with a regular rear there is a flat spot on the carrier that will have your gear ratio stamped it in mine had 6.17 gears they never swapped it out when they but the 673 in it I ended up putting a double reduction 4.61 I think out of a diesel but have since removed it to air ride it Quote If your going to be a bear be a grizzly Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514066 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 17 minutes ago, h67st said: Jack one rear wheel up and spin one revolution, count how many times the driveshaft spins and divide by two (such as 9 driveshaft revs would be a 4.50 diff ratio). I’ve done that with old Fords before. What’s the gear ration for a gas job or the Thermodyne diesel? Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514069 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 18 minutes ago, Mean Green said: is yours a single axle or tandum mine was a single axle with a regular rear there is a flat spot on the carrier that will have your gear ratio stamped it in mine had 6.17 gears they never swapped it out when they but the 673 in it I ended up putting a double reduction 4.61 I think out of a diesel but have since removed it to air ride it Single. I’ll have to check when I get it home next week. Paid for it today, just gotta line up a ramp truck for the weekend. Guy I know has a landall but not sure he’s got a winch. I’m gonna call a guy who’s got a ramp truck too to see if he’s available. Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514070 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 I’m trying to upload some pics that I took today but I’m getting a “server error -200” when I upload. I’ll get them in here soon though Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514071 Share on other sites More sharing options...
Mean Green Posted October 30, 2022 Share Posted October 30, 2022 if you need rear I have one that was out of my truck don't know where your from but it's just laying around Quote If your going to be a bear be a grizzly Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514072 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 1 minute ago, Mean Green said: if you need rear I have one that was out of my truck don't know where your from but it's just laying around That’s awesome! We’ll see what it’s got when I get. I appreciate the offer. I’m in Massachusetts, where are you located? Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514073 Share on other sites More sharing options...
Mean Green Posted October 30, 2022 Share Posted October 30, 2022 I found if you post pics from your cell phone they take up too much of what you can down load to this site I screen shot the to make them less mb Quote If your going to be a bear be a grizzly Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514074 Share on other sites More sharing options...
Mean Green Posted October 30, 2022 Share Posted October 30, 2022 near pittsburgh if you can use it you can have it it also has 4 tubeless rims with it Quote If your going to be a bear be a grizzly Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514075 Share on other sites More sharing options...
Craig N Posted October 30, 2022 Author Share Posted October 30, 2022 15 minutes ago, Mean Green said: near pittsburgh if you can use it you can have it it also has 4 tubeless rims with it Road trip! Haha, thanks. I’ll see what I got in mine first. Much appreciated! Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514076 Share on other sites More sharing options...
Mean Green Posted October 30, 2022 Share Posted October 30, 2022 no problem good luck on your project Quote If your going to be a bear be a grizzly Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514077 Share on other sites More sharing options...
Popular Post Craig N Posted October 31, 2022 Author Popular Post Share Posted October 31, 2022 3 Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514105 Share on other sites More sharing options...
Craig N Posted October 31, 2022 Author Share Posted October 31, 2022 22 hours ago, Onyx610 said: Or Cummins ISC 8.3 Thanks, Onyx. Too bad that 350 I have is too big! Ah well. Hopefully I can get the 673 unstuck Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514110 Share on other sites More sharing options...
JoeH Posted October 31, 2022 Share Posted October 31, 2022 (edited) I've got a 237 with a 5 speed mack trans bolted to it. Engine smokes a bit, doesn't like to start in the cold. Most everything else on the truck is gone, and we haven't had it running in a few years. Was a U675T, I think 1974 or 1976. If your engine is no good then send me a PM, I can check with my dad to see if we want to sell it. Zip code 18914. Edited October 31, 2022 by JoeH Quote Link to comment https://www.bigmacktrucks.com/topic/70634-350-cummins-in-a-b-42-is-it-a-possibility/#findComment-514113 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.