I have started to do alot more heavy towing with my truck, and I can't help but wonder how much nicer a 6spd would be for the closer gear ratios. I already have a 13" dual disk and 1 3/8" billet input, so I was thinking that all I would need for the swap would be altered driveshafts, extended linkage for the t-case, and maybe a different crossmember for the mount? Any input would be appreciated, Thanks

 

I think you have it about right, but I would actually recommend keeping your five speed really; and going to 4.1 gears in the rear end if you don't already have them. Reason being is that the 6 speed is dramatically more expensive to maintain and repair than the 5 speed is.
My .02 of course. And by the way, I really do love the six speed...

 

The only difference between the 2 is 4th gear on the 6-speed, otherwise everything is the same. I agree with Mishkaya, the 6 speed is expensive to maintain and if you do get one, make sure that you get one with the 1 3/8" input shaft, not the one with the 1 1/4" shaft, they can't handle as much power.

 

I had also thought about deeper gears, but since I still do alot of empty highway driving as well, I didn't really want to give up the fuel economy. I did some comparing of the ratios of the two trannys and it's actually more than just 4th and 6th.
Gear Ratio
1st 5.63
2nd 3.38
3rd 2.04
4th 1.39
5th 1.00
6th 0.73
R 5.63

Ratio 5.61 3.04 1.67 1.00 0.75, and it was 5.03 for reverse
I was under the impression that the 6spd is actually stronger as long as your not trying to race? And I really don't want to have to put more money into my 5spd, already have alot more than I'd like to admit I was thinking that I should be able to come pretty close to offsetting the cost of the 6spd by selling the 5spd Just to be clear though, this is all just curriosity at this point, I will have to talk to the guy that does all my work to see what his opinion is if I get that serious. Thanks guys

 

Stock for stock the 5600 is stronger than the 4500. However, it is also more expensive to fix and replace. I'd say about 1.5-2 times the cost of the 4500. But other than the clunky shifting and the tendency of the third gear synchro to grind when its cold, the 5600 really doesn't have any major issues.

Does your 2000 have a wide cross member with 2 sets of slotted holes? If it does then you can use the same cross member. The only other differences would be drive shafts and the T-case Linkage.

The 5600 is a porker at about 420 lbs.

Only the very early 6 speeds had the 1 1/4 input shaft. 01 and up should have the bigger input shafts.

 

And if I got a newer one I could just re-use my current 13" dual-disk and billet input, correct?

 

I doubt you could use the 4500 input in the 5600. There is really no need to if you could. But the clutch should be the same.

 

I thought that the oversized-1 3/8" input used for the 13" clutch in the 5spd was the same input used in the 6spd? And I was just thinking that if I already have parts that would work, a billet part to boot, that would be less stuff I would have to buy to perform the swap if I decide too. Thanks for the input, I appreciate it

 

Ok, i have went from 5600 to built auto to 4500 to 5600, yes i ahve done it alot, if you have the wide 4slot cross member then like Kazairl said all you need to do is do the shafts, the t-case linkage is adjustable and does not need to be changed out. Your billet although the same size will not fit the 5600, you can sell it and the trans to offset most of the cost. I got my 5600 as a core for 1200.00, all it needed was the 5-6 syncro, fixed it and she runs like new. The key is to have good fluid and make sure you put a filter on it to keep it that way. Although the 5600 is more expensive to fix it is is much stronger than the 4500, although people say parts are hard to come by, i had no trouble finding anything i needed for it. I would say go for it if you can, call the salvage parts yards and pick up a decent core that is not in pieces, unless you can get a deal on a good used one. Let me know if i can help you out.

Chad

 

Cool thanks, bummer on not being able to use the input. Guess I will have to call my mechanic sometime and see what he thinks it may cost me. Thanks again guys

Oh yea, how do I tell which crossmember I have?