Gen 1 Small Block Swap?

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OldFarmTruck22
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Re: Gen 1 Small Block Swap?

Post by OldFarmTruck22 »

thej10guy wrote: Thu May 04, 2023 9:36 am I’m guessing you will not listen to this information because it’s not exactly what your requirements are, but I doubt there are many people active on hear that can answer your question. I have a 4l60 with a 241c in my truck which is the same length as a 700r4/241c combo would be. With my factory tank and centered rear axle I had plenty of clearance between the tank and driveshaft, and there was quite a bit of room between the tank and transfercase lengthwise as well. I don’t know about your offset rear axle question although I am pretty sure other people have run the 241c with the offset rear axle. As far as passenger side drop, it will clear everything (oil pan, etc). I have a passenger side drop 241c t case behind a 700r4 and 350tbi in a k5 blazer, so no matter what vehicle you put it in, it should clear just fine.


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thej10guy: I'll absolutely listen to what you posted, because you speak from experience on the topic I posted, without twisting my post into some other solution. THANK YOU for what you just posted. It answers a few of my questions BEFORE I buy a 241c and make my plans to do the swap. That's how I work, I get feedback BEFORE I tear down a running vehicle and find all kinds of surprises because I didn't ask in advance. I like to have 'my ducks in line' first.
So Thanks j10guy, good to know there is clearance right there at the corner of the gas tank for the NP241 to fit in place. I'll worry about the offset rear axle as I go along. From what I have read on the old website and some old posts here, there are members who kept the offset rear axle.
78 FSJ AMC 360 Quadratrac
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thej10guy
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Gen 1 Small Block Swap?

Post by thej10guy »

Here is an old link talking about this swap into a 75 waggy (so it would have the same frame/gas tank as yours I presume).

viewtopic.php?t=15756

I think, if you are concerned about the rear tank clearance by the t case, as long as you mount it far enough forward there should be nothing to worry about.

I’m sure there is other links out there too but this is the first one I found talking about a 350 with 700r4 swap. I would assume 241 vs 208 would be pretty similar dimension-wise.

It’s not exactly what you are asking and it doesn’t directly address the fuel tank but I assume if the fuel tank was an issue it would be mentioned.


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1983 Jeep J10 Honcho SWB 5.3 4l60E NP241C viewtopic.php?f=12&t=22361
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Topic author
OldFarmTruck22
Posts: 244
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Re: Gen 1 Small Block Swap?

Post by OldFarmTruck22 »

thej10guy wrote: Fri May 05, 2023 8:18 pm Here is an old link talking about this swap into a 75 waggy (so it would have the same frame/gas tank as yours I presume).

viewtopic.php?t=15756

I think, if you are concerned about the rear tank clearance by the t case, as long as you mount it far enough forward there should be nothing to worry about.

I’m sure there is other links out there too but this is the first one I found talking about a 350 with 700r4 swap. I would assume 241 vs 208 would be pretty similar dimension-wise.

It’s not exactly what you are asking and it doesn’t directly address the fuel tank but I assume if the fuel tank was an issue it would be mentioned.


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j10guy, the driveline dictates how far forward the transfer case will sit. I can't/won't be relocating motor mounts to move my engine forward. the BW1339 with the low range unit is pretty close right now, so I have to know what I'm getting into before I tear it all down.
Thanks
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thej10guy
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Re: Gen 1 Small Block Swap?

Post by thej10guy »

I thought you didn’t have the 350 installed and were planning on installing it…? Maybe I am confused. I assumed you had a amc engine and were gonna put in the 350 which would require custom motor mounts which you could locate anywhere on the frame (within reason). This, in theory should give you a few inches of travel from front to back.


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1983 Jeep J10 Honcho SWB 5.3 4l60E NP241C viewtopic.php?f=12&t=22361
1979 Jeep J10 LWB (project/parts truck)
1989 GMC Jimmy (project)
Jeep Lover for life :fsj:

Topic author
OldFarmTruck22
Posts: 244
Joined: Sat Mar 05, 2022 4:35 pm

Re: Gen 1 Small Block Swap?

Post by OldFarmTruck22 »

thej10guy wrote: Mon May 08, 2023 12:17 pm I thought you didn’t have the 350 installed and were planning on installing it…? Maybe I am confused. I assumed you had a amc engine and were gonna put in the 350 which would require custom motor mounts which you could locate anywhere on the frame (within reason). This, in theory should give you a few inches of travel from front to back.
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Yes I do have a smallblock I can install, but the oilpan clearance to front suspension, etc. will dictate how far forward I can move it. A 700r4 mated to a NP241 will require an adapter also. That will move the transfer case further back also, possibly interfering with the gas tank.
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Yeller
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Re: Gen 1 Small Block Swap?

Post by Yeller »

You will push the fan though the radiator before the oil pan is the issue.

Somewhere I have charts that show all of the dimensions for the exact drivetrain you are proposing, I’ve just not been able to locate them but will keep looking
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Topic author
OldFarmTruck22
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Re: Gen 1 Small Block Swap?

Post by OldFarmTruck22 »

Yeller wrote: Tue May 09, 2023 10:26 am You will push the fan though the radiator before the oil pan is the issue.

Somewhere I have charts that show all of the dimensions for the exact drivetrain you are proposing, I’ve just not been able to locate them but will keep looking
Thanks Yeller.
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