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Right now i have a torn down 350 and i know the person who has the original motor out of my 1977 blazer which is a 400. I was gonan turn the 350 into a 383 stroker but i would like to have a 400 also. I was just wondering what would be better for the mud?
 

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Really 400 just has a bigger bore thatz about it it all depends on wut u have in the motors myself i would go with a 383 but thatz just me or bore out the 400 to a 406 and run that
 

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I just had this conversation with a friend of mine. a 383 builds torgue which would be good for mud but in my opinion if you dont have alot of money in them the high rpm will tear it apart. ive learned in mud you want alot of horse and torque when i use to drag race i did alot of research on 400 and if you use 5.7 rods nothing cheap,a good set of heads, and cam it up i dont think you will be disappointed.
 

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400's are less reliable because of there inability to keep cool when putting down higher hp and tq. due to there siamesed bores they tend to overheat. i personally would go with the 383. summit racing has a 3.75" stroker crank for a 350 for around 200-300 bucks. it's only cast so it's not as strong as a forged piece but it can still withstand a good amount of abuse
 

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stock 400 won't hold rpm like 454 bbc's due to externally ballanced. unless you spend the $ and ballance them. 350 is all around cheep small block build.
 

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Myself, I would go with the 400 and NOT bore it unless you have to. Oviously you'll get more torque, as well as the ability to make more power. I don't play in the mud at all, but it was my understanding that wheel speed is key to keep the wheels turning and "cleaning" out the tires? Correct me if I'm wrong, I don't know first hand.
There are plenty of 400 builds running around with no overheating issues whatsoever, you just need make sure everything is in proper working condition.
And obviously nothing is going to hold together for very long if the build isn't done correctly. You need to weigh how much you can spend, and how hard this is going to be driven.
Also keep in mind a bigger motor will be more streetable than a smaller motor with the same parts (heads/cam/etc.)
 

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everyones going to have there own opinion just do the research and build whats best for what your going to do because there so many options you could sell both the sb and buy a bb:sonicjay:
 

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I'd go with the 350, just build it up, it's the best all around small block, it's easy and cheap to maintain and cheap to build. and it has the potential to produce plety of power for any mud truck you might build.
 

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I would not choose a motor known to run hot and then throw it in an application where it will get covered with mud and insulated, effectively killing its ability to radiate heat.
If done right/correctly, a 400 will NOT overheat. I have seen a TON of high HP street cars run 400 based SBCs with NO overheating issues whatsoever. I also know of at least 1 person with a 400 SBC that does do a lot of mudding with no overheating. We ran a 406 in dads Jeep, and even on the HOT days at the dunes, no overheating issues. Insulating a motor with a layer of mud can cause an overheating issue with any setup.

I'd go with the 350, just build it up, it's the best all around small block, it's easy and cheap to maintain and cheap to build. and it has the potential to produce plety of power for any mud truck you might build.
If that's the chosen route, I would at least go to a 383. You'd see a noticeable difference between the two given the same setup. My biggest reason here would be torque. I'm assuming a mud truck is going to run some large tires/etc., so the more torque the better.
 

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the biggest reason why 400 SBC's over heat easyer is cylinders are siameased or conected togerthe unlike other engines. why they have more steam ports in heads and block to try to help with this.
 

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If done right/correctly, a 400 will NOT overheat.
There's the problem right there. How often do you see that happening around here? :sonicjay:


I agree that mud insulation can happen to any motor, but the degree of sensitivity can vary greatly.
 

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the biggest reason why 400 SBC's over heat easyer is cylinders are siameased or conected togerthe unlike other engines. why they have more steam ports in heads and block to try to help with this.
I think the biggest problem was people swapping heads and NOT drilling the steam holes.


There's the problem right there. How often do you see that happening around here?
I don't know what you're talking about, I can't have more than 100 zipties and 1 roll of duct tape on my Jeep! :sonicjay:
 

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I had a well built 383 and my buddy had a well built 400 and the 383 out performed the 400 with ease and the builds where not that far apart as money spent goes. The 383 is more economical because of the origination of it (350) and you can get more bang for your buck. If you choose the 400 then just make sure all of your steam holes are drilled and you will have no temp problems. Good luck.
 

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I would not choose a motor known to run hot and then throw it in an application where it will get covered with mud and insulated, effectively killing its ability to radiate heat.
But a larger motor is greater in Hoss than a smaller motor.
 

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I had a well built 383 and my buddy had a well built 400 and the 383 out performed the 400 with ease and the builds where not that far apart as money spent goes. The 383 is more economical because of the origination of it (350) and you can get more bang for your buck. If you choose the 400 then just make sure all of your steam holes are drilled and you will have no temp problems. Good luck.
I'm not sure where the logic in that lies?? Pretty much when you buy something for a SBC, it fits a SBC. The heads, intake, cam, rods, bla bla bla pretty much all interchange. How is a 383 more economical?

Really, you should get more "bang for your buck" with the 400. Unless the build is waaaay off, you're gonna make more power with more ci.
 
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