C6 to NP Swap Thoughts

Clutch, transmission, rear axle

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ToughOldFord
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C6 to NP Swap Thoughts

Post by ToughOldFord »

As some of you that have following some of my posts may know I'm planning on upgrading my '69 from the C6 to a NP. I have everything I need now, just need the time. I might wait until spring so I'm not lying in the mud doing this.
I do see a few negatives and possible problems to this:

1) Negative. No more hump console for storing things and drink holders and tach mount. :(

2) Possible problem. As close as those shifters come to the dash I hope my A/C unit doesn't get in the way. I'm not giving up my A/C.

3) Annoyance. I'm 6' and my truck has the large steering wheel. That doesn't leave much room for leg articulation to work that clutch pedal.
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Post by 19674x4 »

whats there to think about. lol do it. im 5'10, so basically almost 6 ft. and i can still work the clutch fine.
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re: C6 to NP Swap Thoughts

Post by ToughOldFord »

:lol: I'll get it done, one way or the other. I was just sitting in my truck and looking over what's going to change and I noticed If I put my left leg on the floor it has very little room before it hits the wheel. Guess I have to keep the leg leaning over to the left. :dk:

On the plus side my cab already has the factory hole in the floor for the manual transmission. I'll just have to switch the plate. :thup:
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Post by fordman »

man just cut a hole in the steering wheel big enough to get your knee through it when you clutch. :lol:
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re: C6 to NP Swap Thoughts

Post by ToughOldFord »

:lol: Good ol' ingenuity. :clap:
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Post by averagef250 »

I'm 6'3 and fit in these trucks great. All my trucks have manuals. The room is probably one of the big reasons I like them so much.

The shifter will clear the AC fine.
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re: C6 to NP Swap Thoughts

Post by ToughOldFord »

Couple of questions, is the cross member for the C6 the same or should I use the one off the NP?

I assume I'll need a different driveline, correct? The C6 looks to be quite a bit longer than the NP. If I do need to replace mine is it save to assume that I only need from the carrier bearing to the transmission instead of the entire driveline?

:fr:
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Post by fordman »

the crossmember is the same one for all transmissoins. the front driveshaft is what you will need. it will be longer than the c6 driveshaft.
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re: C6 to NP Swap Thoughts

Post by ToughOldFord »

Thanks Fordman. :thup:
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re: C6 to NP Swap Thoughts

Post by ToughOldFord »

Getting close to starting this swap, yesterday I was feeling around on the drivers side frame to see if the holes for mounting the Z bar were already there or not. There's a lot of crud up there, but it feels like they are there. Is that correct for the factory automatics to have the Z bar holes in the frame?
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re: C6 to NP Swap Thoughts

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Yeah, Nevada's pretty good for rust free vehicles and parts.
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re: C6 to NP Swap Thoughts

Post by H-DFord »

Just found this tread and was wondering why you are replacing your c-6. Reason I ask is i've wondered if I go with a manuel would it help my gas mileage. Or does the standard have other benifits to you. The c-6 behind my 360 does seem to keep rpm's up. Also, is NP a type of manuel trans. I was thinking for my truck of trying to find a 5 speed and hopeing that would up mpg. Thanks for any insite you can give me about this. John
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re: C6 to NP Swap Thoughts

Post by fourtss »

Hey John, just a few words for some thinking, the NP trans is a 4 speed w/the granny low (1st gear) it won't improve your fuel milage any, you will improve fuel by changeing gear ratio in the rearend, however if u have 4x4 I would not suggest doin that, if I'm not mistakin (and I very well could be) the gears in a 4x4 are like a match set, I know someone with more expierence in 4x4 can help u out better on that, the np tranny will give u the same milage as the C-6 tranny, to up your fuel, u may want to go with a3:25 or maybe a 3:08 ratio, I have heard there is even 2:85 gear ratio but not possitive on that, I'm sure that if u do some investigation on the this website you should find more info on it, or someone chime in and give u more info :thup: hope this helps u
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re: C6 to NP Swap Thoughts

Post by H-DFord »

Ok Thanks for that. Mine is a 2 wheel drive so ill look at other rearend options. John
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re: C6 to NP Swap Thoughts

Post by ToughOldFord »

Changing from the C6 to the NP will improve mileage, although I don't know if it'll be enough to justify the swap. Manual transmissions get better mileage than automatics as a rule, you're not wasting HP (and fuel) to run the pump and the torque converter so you're using your HP and fuel more efficiently. And although the C6 is about as bullet proof as an automatic can get it is known as a HP (read fuel) hog.
However; Tom's right as far as you won't gain mileage as a result of lower RPMs with a NP, the final ration is 1 to 1, the same as the C6. If you want to drop the RPMs via the transmission you would need an overdrive unit or a gear vendors.
Changing your rear gears may be an option, but if you tow be careful not to go to high, (low numerically), but for myself I went from 4.10 to 3.73 and it dropped my highway RPMs by 200 but I saw zero improvement in MPGs.

My swap here is sort of an experiment, I am curious to see what kind of mileage gains I'll get with the manual, but I also prefer manual transmissions in trucks over autos anyway so either way I can't loose. I'll report the results here.
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