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Discussion Starter #1
i have been offered 2 300 straight 6 motors i am tossing around the idea when my 351m dies of installing the 6 i dont off road just a get around town ride and pack the kids instead of driving my 97 f350 7.3 diesel i think i would be happier with the better gas milage i also noticed a article in the bronco driver magzine this month seemed to really interest me thn today i was offered 2 for free 1 running 1 needs rebuild anyone do this conversion in a bronco???? and if so how is it working out also will this mate to C-6 automatic trans??? any info would be great thanks
 

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the 300 uses a diffrent bellhousing pattern than the 351m, 400, 460 does. You could get a c6 from a 302, 351w or a 300 to make it work. You would also need motor mount towers ect to make it bolt in, but you can get all that from a 78/79 f-150 that came with a 300. IMO, the 300 is one of the best engines ford put in the trucks, not fast, not uber powerful, but they are great engines.
 

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My 300 is as good on gas in town as my safari mini van.lol On the highway there is no comparison.lol A four barrel carb instead of the one barrel that is usually on them, I think would improve gas mileage in town and highway.
 

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I built a '83 Bronco with a carbed 300 and a '95 5-speed that I swapped in, and that thing got about 20 mpg. As long as I kept the speed down. The aerodynamics of a Bronco aren't the greatest. Somewhat like a solid block of steel rolling down the highway.
The only thing better than the 300 for fuel mileage is a diesel.
 

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My 300 is as good on gas in town as my safari mini van.lol On the highway there is no comparison.lol A four barrel carb instead of the one barrel that is usually on them, I think would improve gas mileage in town and highway.
Some minor port and bowl work on the head, a torque rv cam, offy intake with 390 holley 4V, and a header with a free flowing exhaust is the hot ticket for better performance and fuel mileage.
 

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But try to find a good small block 4x4 C6. not impossible, but far between.

The 300 does it's job so long as you treat it right. It'll do anything you want it to at 55mph, just don't be in any hurry. I'm running a consistent 14/17 split with a carbed 300 in an 86 supercab 4x4, my first truck was a 4x2 85 with a 300-6, a 435, and 3.08's- it brought back 23 mpg highway all day, every day and had good in town economy as long as you kept it under 1/2 throttle (15/23 split). Heavy on the throttle and you were getting single digits in town, easily.
 

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Discussion Starter #7
thanks for the replys
so there are 2 styles of c6??
if i was going to use it i am going to do some hp upgrades like what american thunder had mentioned i was going to do some more research on
i am also concerned why cant you go over 55 on the highway?? with the upgrades will it be ok to do 70-75??
 

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He did not say that you cannot go over 55, just don't expect to tow anything heavy over 55.

My stock 77 300 will easily peg the speedo at 85.

There is a 302/351/300/240 C6 bellhousing, a 351/400 bellhousing, and an FE bellhousing. there is also 2wd and 4wd cases.
 

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Exactly, i can bury the needle if i want to but when towing it likes to sit right at 55-60. Try to run it any harder, it just makes noise and burns gas. The 300 has a nice flat power and and from experience, brings it's best economy if you set your truck up to cruise between 2200 and 2500 RPM. Under that and it lugs, above that and you're just dumping gas.

With a direct drive transmission (like a C6), this truck will probably be set up for 60 MPH anyway. A 300, 3.5's and 31's with a 1:1 likes to run at 60. Over that it screams, under that it just pulls itself back up to 60. With 235's it's a 55mph truck.

Yes, it will go faster, but it won't be it's "natural" speed.
 

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Discussion Starter #10
i will not be towing anything with this bronco thats why i have f 350diesel im just looking to crews around highway and take the kids around
so a later c-6 will work will i have to get driveshafts cut and trans fit issues?? or will it bolt right in??
 

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What kinda mileage does the diesel get?
It will be hard to beat it with a 300. One of the reasons I have been thinking about doing a diesel swap is for better fuel mileage.Some of the 1 ton diesel broncos here are apparently getting over 30/gal.
I do love my 300 but its not a highway truck,just in town and trail.
 

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What kinda mileage does the diesel get?
It will be hard to beat it with a 300. One of the reasons I have been thinking about doing a diesel swap is for better fuel mileage.Some of the 1 ton diesel broncos here are apparently getting over 30/gal.
I do love my 300 but its not a highway truck,just in town and trail.
I average 20-22 mpg with a C6 and 9" lift with 35" tires. I also have the pump cranked up quite a bit. If it had stock suspension and tires, with a 5-speed, and the stock diesel, I imagine it would average 25+ mpg.
 

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I was not aware of different C6 cases for 2wd vs 4wd. Only different output shafts and tailhousings/transfercase adapters.
I was told by some transmission guys that the tailshafts and housings will swap back and forth, and that the rest of the C6 is the same. They also told me that you have to take a lot of stuff apart to change those pieces..
 

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It's a shame Ford never put a roller lifter cam in the 300.. That would've been amazing.
 

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There seems to be some good knowledge in here about the 300. Been searching for days and cannot find enough information to move forward with my planned mod. I just picked up an '83 myself with a 300, C6, NP208F. It idles very poorly and produces a lot of black smoke. My best guess is a carb rebuild would be in order. However, I have been reading on Classic Inlines about the 2V 2100 carb swap in place of the 1V carb on there now. They don't really talk too much about the 300 on Classic Inlines when it comes to this modification. Has anyone here done it and what path did you follow? Will be cruising the junk yards on Saturday looking for the 2100 but what carb adapter should I be looking at? Classic Inlines sells carb adapters and list one for a 1.5" bore and 1.75" bore.

http://www.classicinlines.com/proddetail.asp?prod=FSP-200-HCA-D

Thanks for any help you guys can offer.

Fred
 

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I HAD A 460 IN MY 78 BRONCO WITH 4 SPD.,
GOING TO REPLACE WITH 300 CID,
IM TAKING IT OUT OF A OLD SWATHER ,THEY HAVE THE INDUSTRIAL ENGINES WITH THE FORGED STEEL CRANK,AND WEEW GOING TO RUN THE S#ttt OUT OF HER AND SEE IF WE CAN HOPE FULLY WE CAN GET THE REVS UP TO BLOW THE DOORS OFF THEM STOCK 350 CHEV.
 
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