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85 K5 drivetrain dilemma

SPLATT

SPLATT

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I'm in the early stages of build my Blazer and have hit a bit of a snag in the planning. By the time I get to building I usually have a plan as to what combination of parts and pieces to use but not this time. My planned use is primarily overlanding and medium duty wheeling. My dilemma is the transmission/transfer case combo mostly the transfer case. My only requirements so far are no NP203 t-case, or 700R4/4l60e and must have overdrive. The transmissions I've come up with are a NV4500, TR4050 and a 4L80e. For a transfer case I'd love to go with a Atlas case but cost is a bit of an issue so I've been looking at NP205 cases, the JB Conversions Lomax 205 and the ORD Magnum/205 setup. How do the NP208 and NP241 cases hold up to the kind of use I'm looking to do?
 
The 241 is the winner by a long shot here.
Lomax is extinct.
Magnum 205 is pretty dang long for a blazer that needs to be rock solid reliable on road.
Atlas is for jeeps.
208 is a close second.
 
obijuank5 said:
The 241 is the winner by a long shot here.
Lomax is extinct.
Magnum 205 is pretty dang long for a blazer that needs to be rock solid reliable on road.
Atlas is for jeeps.
208 is a close second.
Click to expand...

The Magnum 205 can't be much different in size from a 203. The Atlas wasn't on the radar due to cost and I don't think I'll need that much transfer case. How do the 241 and 208 stack up to the 205?
 
If you're lifted a little, the rear shaft gets short quick. Driveline length needs to be a consideration when asking it to be able to drive across country.
The 241 is arguably a superior tcase. Especially for how youre going to use it as a single.
I can literally discuss this for days.
 
obijuank5 said:
If you're lifted a little, the rear shaft gets short quick. Driveline length needs to be a consideration when asking it to be able to drive across country.
The 241 is arguably a superior tcase. Especially for how youre going to use it as a single.
I can literally discuss this for days.
Click to expand...

Thank you. I think I'm set for the t-case now I just need to figure out which tranmission.
 
Any of them are fine if they dont shift themselves lol
 
What size tire? What engine? If you aren't rock crawling stick with a np241, if you want to row gears either a nv4500 or a late model nv3500 are great choices. Using a manual cam also help with axle gearing, I ran a nv3500 in my k5 with 37's and was able to run stock 4:10 gears. If you want to overland with it there is a balancing act in parts to keep good highway manners.
 
SPLATT said:
I'm in the early stages of build my Blazer and have hit a bit of a snag in the planning. By the time I get to building I usually have a plan as to what combination of parts and pieces to use but not this time. My planned use is primarily overlanding and medium duty wheeling. My dilemma is the transmission/transfer case combo mostly the transfer case. My only requirements so far are no NP203 t-case, or 700R4/4l60e and must have overdrive. The transmissions I've come up with are a NV4500, TR4050 and a 4L80e. For a transfer case I'd love to go with a Atlas case but cost is a bit of an issue so I've been looking at NP205 cases, the JB Conversions Lomax 205 and the ORD Magnum/205 setup. How do the NP208 and NP241 cases hold up to the kind of use I'm looking to do?
Click to expand...
You kinda described what I do with my K5. Sees a lot of road miles and mid-level wheeling. Not full-blown rock crawling, but I've been known to end up on a trail that needs some skill too. 5 years I ran the 700r4/241 combo with a 5.3. The t-case was rock solid even without an SYE on the rear output. The low range gearing really made up for the lack of torque the 5.3 made down low when crawling around on the trail. Fast forward and the drivetrain in my rig was changed radically in the last few months. The item that stayed was the 241. Now with the 8.1 and nv4500, I've got all the torque I need when I want it. The low gear in the 241 is the bonus. I haven't wheeled with this combo yet as I'm still finishing up on little things, but I expect it to be right where I want it. Even with the higher gear 1st in the later 4500 I have the 241 still makes up for it and gives me a better crawl ratio than my buddies with 205's and 4.56's when I'm running 4.10's. We all have 4500's and 8.1's so even with the lesser gearing in my axles the 2.72:1 should really crawl good. I'm looking forward to coming down steep downhill runs and not riding my brake like I did with the automatic.

For no more than I hit the rocks, the 241 will do just fine and really don't justify losing the crawl ratio with the 205's crappy low range gearing for me. Make sure you get a skid plate for the 241 if you go that way. You can't get away with letting the whole truck rest high-centered on a rock at the t-case like one can with a 205.
 
83ChevyK5Blazer said:
What size tire? What engine? If you aren't rock crawling stick with a np241, if you want to row gears either a nv4500 or a late model nv3500 are great choices. Using a manual cam also help with axle gearing, I ran a nv3500 in my k5 with 37's and was able to run stock 4:10 gears. If you want to overland with it there is a balancing act in parts to keep good highway manners.
Click to expand...

I'm looking at running 35"- 37" tires with 4.56 gears maybe 4.88 in the 10b/14b ff and a LQ4 6.0 with a slight bump up in camshaft. I have a LQ4 in my 02 Silverado and have really liked that engine and feel that it would work really well for this rig as well. Currently the truck has a 350 of unknown build specs, a th350 trans, a np203 t-case with a 10b/14b ff with unknown gears.
 
SPLATT said:
I'm looking at running 35"- 37" tires with 4.56 gears maybe 4.88 in the 10b/14b ff and a LQ4 6.0 with a slight bump up in camshaft. I have a LQ4 in my 02 Silverado and have really liked that engine and feel that it would work really well for this rig as well. Currently the truck has a 350 of unknown build specs, a th350 trans, a np203 t-case with a 10b/14b ff with unknown gears.
Click to expand...
While I don't have actual experience with this combination, I believe that you may want to decide which tire size before you finalize your gear choice. I personally would go with the 4:88 gears for either, but I did talk with a guy who has 4:88 with 35s and kept thinking that it was too low. He has a stock cam in his 6.0 with a 4L80E behind it. I honestly haven't driven it on the highway and not with it loaded with gear.
I am getting close to putting a Texas Speed cam into an LQ9 and installing it into an '01 K2500. But with my work pace and the holidays, I am probably well over a month away from driving it. I bought a cam that is aimed at moving the power band down some and giving it a small bump as well. I am very excited to see what happens. I am going to put a shift kit into the 4L80E when I get it rebuilt too. Hopefully that gives the results that make me happy. But I can't give you any personal experience to help with a decision right now.
 
6872xtc said:
While I don't have actual experience with this combination, I believe that you may want to decide which tire size before you finalize your gear choice. I personally would go with the 4:88 gears for either, but I did talk with a guy who has 4:88 with 35s and kept thinking that it was too low. He has a stock cam in his 6.0 with a 4L80E behind it. I honestly haven't driven it on the highway and not with it loaded with gear.
I am getting close to putting a Texas Speed cam into an LQ9 and installing it into an '01 K2500. But with my work pace and the holidays, I am probably well over a month away from driving it. I bought a cam that is aimed at moving the power band down some and giving it a small bump as well. I am very excited to see what happens. I am going to put a shift kit into the 4L80E when I get it rebuilt too. Hopefully that gives the results that make me happy. But I can't give you any personal experience to help with a decision right now.
Click to expand...

I'd say if you're going to re-gear then do it once and be done with it. If you're in between two tire sizes you can almost bet that at some point you'll get the bug and want to go bigger. Running 35s with a 4.88 will be fine if you have an overdrive. A lot more people regret having too little gear than too much.
 
Just showing mph and rpm with an overdrive.
I would love a 4l80e and a Magnum but making the the trans work and mate to tcase would be more money than the truck is worth. Be easier and cheaper to to driver side drop with a complete donor driveline
 
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