Ok, so I bought this Bronco....It was supposed to be in good shape.....It wasn't. Anyway, it has an in-line six in the 4.9L-300long block flavor. LOW END TORQUE....thats what I hear people rave about. More low end torque than a 302 and similar v8's...I hear that too. Clifford Performance tells me that they can give me around 400 ftlbs at around 3400rpms and keep 80% of the torque at under and around 2000rpm. That sounds good to me. Does anybody have a testament to back this up. I must rebuild my 300L6 or swap it out with a V8 because it needs rebuilt in order to function at present. Decisions, decisions. While contemplating a motor rebuild or swap out i started contemplating transmissions too. The end goal is to crawl, climb, dig, slide, and spin around in the mud with 44" boggers. Thats why the low end torque appeals to me. I dont want a high revving motor while Im doing 5mph through the mud. I looked at the motor and the C6 tranny attached to it and thought about regearing. The stock 8" axles have a 3.55 gearset that I thought about upgrading to a 4.56 inside of a pair of Dana 60's. I then thought about changing my trany and t-case out from a C6/NP208 combo to a NP435/NP205 combo. If I do the trany swap and beef up the inline six I thought that combonation would give me a mud monster...what do all you gurus think?  

I don't have the torque figures in from of me but the 300 I6 is a torque monster to start with, so I would think a build dedicated to torque could reach those figures. 302's are great Mustang motors, but aren't the best for trucks. A 351W can be built up very easily with more torque and HP, but the I6 will be better on gas. I'm not much on gearing, so I'll let someone more knowledgable than me tackle that, but I think you would indeed have a mud monster with all those mods.  

Thanks for the input, I believe the 6 will be a better choice in the long run for what I want, but its not gonna be good on gas at all! Its gonna have a Holley 4brl carb custom jetted on a custom manifold pouring gas into oversized piston chambers...shes gonna be thirsty I do believe. Clifford also makes 2 & 3 carb manifolds for the 300L6 that would surely suck the gas right outta the tank, but I dont want that (I cant imagine what 3 4brls mounted together would drink?). They advertise up to 700HP for the Inline 6 for race cars, but I want a mud toy I can drive, not rebuild all the time from extreme wear. 400lbs/ft at 300+hp is fine with me.  

If you plan on 44" tires I would go with the 351w and stroke it to 393 or 408 with good heads. A 44" tire weighs around 200lbs or more depending on rim. My 40" hawgs on alloys weigh 137lbs and thats a lot of rotating weight. Not including all the other related up grades to back up a 44" tire. If you stroke a windsor 3.85 stroke is a good set up but if you can go more like 4" is better for low end torque. Or just install a big block and some cool parts. I'm a big block guy and 460 ford OEM can go up to 4.5" safely and that means around 575cubic inch. But this creates more problems with more torque. C-6 tranny with low gear kit or a manual tranny with a centerforce dual friction clutch at the least. Been their done that for heavy mud action on 44" tires. One problem with the 300 six is its longer and some clearance issues will come into play up front and motor mounts. I would go with the 351w over the 300 six due to clearance issues up front. More parts available for 351w than 300six. Good luck and let the fun begin. On the multiple carb set up if done properly will make more torque over a single carb due to more holes to meter the fuel through the venturies of carb. Just requires more tuning but in the end you have equal length runners at intake and better fuel distribution and no lean spots compared to single carb. If you have anymore question drop me a note and good luck.  

If you want really big tire more than ANYTHING, you want serious gears (44's would be 5.57 or 6.14's). This is what makes it all happen. Many focus on engine and not gear which are the real solution as they make the power you do have fully available. Also on this torque thing. 300 have good low end torque because of a very conservative cam and a very long stroke vs bore. Most mid sized V8 cannot match this low RPM torque because to get impressive HP numbers, the sacrifice lower RPM torque and efficiency for gains on top end. When you get into big block by shear displacement they can have good low RPM torque even with a warmer cam and diesel like torque with a mild cam.  

really you get down to it i know no numbers on inline 6 . but until the tranny gave i had a 350 inline6 granny tranny flatbed that on multiple ocassion pulled 22000 lb cnc machine up and down the hills of cincinnati no problem. all the torque you want but it is a long ass motor. they quit makin them cause you cant make money on repair parts if the engine is indestructible  

i don't understand why people think a straigh six is good for mud bogging with 44's. unless you build a high end six you will never be able to get on top of the tire. i would go with a 40 inch tire if you are dead set on running the six. there is not that much difference between a 40 and 44 when they are on a truck in the mud.  

Even a 6 can move a lot of weight with proper gear and more effectively than a V8 with improper gears. In 70's when I was going to college I had a job in construction and I drove MD and HD dump trucks. I drove a C70 with a 427 that did a fine job hauling 20 tons of payload/cargo in bed. I knew this old retired guy that used to do some contract hauling work on Job when we would hire extra dump trucks to haul material quicker. He had a cherry 58 C60 single axle dump truck. It had a 261 six and a 4 speed with a two speed rear axle. He used to haul 8 ton with it all the time with no problems and did for many months on and off. Some loads up to 40 miles. It did will because it was geared properly to use the power it had effectively. It is all about the gears.  

right snow but with the gearing needed to properly turn the 44's he would have no wheel speed to clea out the 44's.  

1978k-20:
right snow but with the gearing needed to properly turn the 44's he would have no wheel speed to clea out the 44's.

I think you miss the point here. I have heard this wheel speed argument many times as a poor justification for tall gears. The purpose of axle gear is to be able to transfer maximum effort to ground at normal operating speeds and have all gears in tranny truly usable. As far as wheel speed in concerned, this is a function of engine peak power and tranny ratios. Some of you guy live with low range off road because your trucks are geared too tall for engine and tires. Myself I like 4x4's geared properly to the point that low range is not needed that much and mostly for when you want to crawl not because of lack of effective gear ratio in hi range due to poor tire/engine/axle ratio combos.  

no i don't miss the point. i know how well trucks perform when geared properly. wheel speed is determined by the final drive ratio. numerically higher gear ratio more torque multiplication less speed. numericall lower gear ratio lower torque multiplication more speed.  

No, it is determined by using a low/deep axle ratios and UPPER gears of tranny to limits of engine power. Not by hamstringing it with a tall axle ratios and hoping for best in lower tranny gears. Deeper axle ratios also improve traction because there is less axle wrapup to drive shaft counter torque at same ground effort and the ground pressure is more even on both tires on axle. With tall gears and the drive shaft torque actually unloads weight off RR tire and puts more on LR and this is way RR always spins first on a open diff and posi tend to swerve to left (drives side) on a hard 2 wheel burn out on dry payment because LR has more traction weight on it and pulls rear end that way. Deeper gear reduce this torque shift at same ground effort and improve overall traction on and off road. Many think though that this has no merit and there is a magic force holding both tires down equally but you cannot fit the physics of it and you can "use" it to your advantage or ignore it and hamstring true potential and stick with tall gears. It kinda separates the true hard core operators from the wanna bee's.  

Well here we go on mud monster. The 300 six is a good engine but in serious mud world you need wheel speed to keep tires clean. Boggers are a awesome tire but sometimes you need to spin them to clean them. I'm with 78K-20 on wheel speed. Also if you get into serious black gumbo your gonna need all the torque you can get when it starts sticking. Also what is the largest clutch you can get for a 300six?? You want a 12" clutch with 44's. If the 300 starts making power and tires don't spin because they are hooking up and clutch will be a issue. Centerforce dualforce is a good setup. Personal experience down on the Brazos and Colorado river in texas and some in Oklahoma. Smoked a few clutches in my day until centerforce came along for big tire situation. One problem with low gears is small pinion's and I like a little taller gear due to pinion diameter and heat dissapation in heavy load situation. busted a few pinions's also Sheared off a dana 60 once. Ford nine inch with stock housing and 5.50 gear or lower will push the pinion out the case with 400ft lb torque 351w. Seen a 360 amc rockcrawler do it also on 39" boggers. I believe in good gearing but serious mud needs a little wheelspeed when it starts to stick!!  

Really for mud running and pulling you need a automatic and DEEP axle gears. This way you can shift up and down on the fly as traction changes rather than trying to do it all in one gear which is a compromise at best.  

Well it has been quite the education to learn how to build the right machine for what i wanna do. I find it difficult at times to find, sort and understand all the information thats out there. I have heard many arguments on what is appropriate for a fun riding mud toy on oversized tires. I appreciate all of your views and advice as all information was helpful. I have been asking similar questions around several different forums with many, many opinions given. All of the information that I have sorted through has led me to these following conclusions: 1)6 OR 8?: A 300 inline-6 is very torquey and can be built to be an impressive "race" motor that is highly competetive with larger V-8's. The down side to this is the excessive cost involved to get a "super-6" as I call it, not to mention the excessive consumption of fuel from the high performance mods. I have found that similar gains can be made more cost effective with a larger motor. 2)GEARING:I have discovered the great things that can be acheived through gearing, such as why a small motor can appear to do so much work. When trying to design my rig to do what I wanted it to do I found out that gears were the "second" thing I needed to consider "only" after I had decided how I wanted to drive my toy. I found out that through gearing my motor size "did not matter" if I wanted to crawl through mud. I could add as many gears as needed to crawl, however, I had to be able to minimize my gearing to spin out. So knowing that I realized that I needed a motor that could give me power at high rpm's (that eliminates the inline-6), that was the exact opposite of what I thought I wanted and needed. I also realized that tossing super low gears into your axles is not the answer. I believe a moderate axle ratio with a wide range transmission and multi-ranged or dual transfer cases is the solution. This is all based on managing the load of large heavy tires like 44" Super Swamper Boggers. I believe that much less would be needed to get the same performance I want if I only ran ..say...36" tires. But because of the increased loading of tire weight and friction from sticky mud, wide gearing and raw power are needed. Now you just need to get sturdy componets to support the wide range of torque thats been created....now comes stronger axles, steering boxes, u-joints, suspension componets such as ladder bars to prevent axle wrap....and the list goes on....Thank you guys for all of your input you have helped me greatly!