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Ideal Drivetrain for Crew Cab and why

But isn't it pretty much given that ALL small block heads are likely warped and possibly cracked at 250,000+ miles? Not just the TBI ones?

I have a friend of mine who still owns a 1970 SS Chevelle, wich came stock with an LT1 4-Bolt main 350. He bought this car in 1978, and the engine hit 800,000 miles in 1985 (the original engine was rebuilt). Head castings were thicker back then in the days of leaded gasoline.
 
Do you guys remember back in late 98 when gm had a contest to give away a brand new 99 Chevy truck? The deal was that you had to bring in a fully documented vehicle. The most miles wins.

The idea was that since they were finally moving to the LS engines full tine in trucks they wanted to know what/where was the highest documented mileage gen 1 small block running around.

If I recall correctly a fellow had a late 70s Chevy van (78?) with 1.3- something Million miles.
That's right people; ONE MILLION THREE HUNDRED THOUSAND and some change. Original.
Last I heard it was in the gm heritage center. ( had to give it up to get the truck)

Now my facts may be slightly off as I am going off memory alone. I know I am close.

Heads were cracked? Most likely. Does anyone care? Nope.

Hijack off
 
Before I posted this I looked around on the intrawebs for about 15 minutes trying to find something, to back me up. Honestly I couldn't. I was hoping that someone else remembered and would pipe up. And we have to remember this was really before the internet was king, it was just gaining traction in the late 90's I mean people were still chating on AOL! lol
 
Just an update. Ended up buying the 8.1L/Allison and Vortec 454/4L80E trucks. I am such a glutton for punishment sometimes :rolleyes:. The 8.1 will probably get parted though because it's running status is unknown and it has been sitting awhile. The Vortec 454 runs great other than needing idler pulleys and an exhaust gasket.
 
Moving forward with this. Going with the 454 Vortec but still debating the use of a 4L80 or NV4500. Then what tcase to use. The NP205 or NP241. Then how do I mate a passenger side drop to drivers side engine/tranny set up? Will a 241 bolt right up? Ideally I would just go 454/4l80e/NP205. But then I hear I need an electronic speedo for some reason. The NP241 has an electronic speedo and would probably bolt up to either transmission. But then how hard is it to convert to an electronic speedo?
 
Moving forward with this. Going with the 454 Vortec but still debating the use of a 4L80 or NV4500. Then what tcase to use. The NP205 or NP241. Then how do I mate a passenger side drop to drivers side engine/tranny set up? Will a 241 bolt right up? Ideally I would just go 454/4l80e/NP205. But then I hear I need an electronic speedo for some reason. The NP241 has an electronic speedo and would probably bolt up to either transmission. But then how hard is it to convert to an electronic speedo?

Any 6 bolt round pattern will mechanically bolt up to either tranny, as long as it has a 32- spline input shaft. NP241 cases from 1990 And 1991 square bodies are both passenger- side drop and set up for electric speedometers. I think an NP205 from those years would also work (but don't quote me on that). I've also heard of folks converting cases electric, but have no expertise in this field.

The VSS is used for controlling the 4L80 and newer engines, also. A 2WD 4L80 comes with VSS built in, I've seen such a sensor added to a 4WD case at least once (but that method leads to inaccurate readings while in low range).

You have several options here.
 
Any 6 bolt round pattern will mechanically bolt up to either tranny, as long as it has a 32- spline input shaft. NP241 cases from 1990 And 1991 square bodies are both passenger- side drop and set up for electric speedometers. I think an NP205 from those years would also work (but don't quote me on that). I've also heard of folks converting cases electric, but have no expertise in this field.

The VSS is used for controlling the 4L80 and newer engines, also. A 2WD 4L80 comes with VSS built in, I've seen such a sensor added to a 4WD case at least once (but that method leads to inaccurate readings while in low range).

You have several options here.

Thanks for the info. I do have a 32 spline NP241 from an SM465 out of a 91 K5. Also, have the speedo from a 91K5. Curious as to how one goes from a mechanical speedo to electric? What kind of wiring is involved?
 
Little late to this party but, I know you posted some on my crew cab build as I went through this entire process of trying to decide the best combo in my truck. All the options mentioned beforehand can work really well, but each have their own level of difficulty and $ added to it. The Duramax/Allison combo is the ends all if you ask me but probably one of the hardest to stab in and the most money. The Cummins/whatever tranny combo works really well and is less money then the Duramax/Allison, but a lot more time in fab for motor mounts, tranny options, tcase options to bolt to the tranny, intercooler mounting, ext. The ZF6 is a really good tranny, but they are really big and you will more than likely have to hack up the floor to get it to fit or throw a larger body lift on it (neither are worth doing in my book).

Comparing the L29 (vortec) 454 to the 8.1, I still would go with the 8.1. Both will get about the same exact gas mileage, both are about the same diffucutly to bolt into a square body and get running (really not that difficult, just fuel and wiring really need to be addressed and that's it), however the 8.1 in stock form puts out ~350 hp and 455 ft lbs while the L29 in stock form puts out ~290hp and just shy of 400 ft lbs. Plus, with just a simple tune on the 8.1 it will really, really wake it up to get almost 400 hp and 500 ft lbs. there are some people who will tune the L29 computer, but you still are not going to get to the numbers of a stock 8.1 with a tune.

I currently have a 96 K2500 with L29 454/4l80e with 4.10 gears that I have been using to tow my K5 in the CO mountains. It actually does pretty good on flats and slight grades, but I slow down like crazy on the passes. Plus, I honestly don't think the 4l80e has that great of gear spacing between 3 and 4 either, just like the NV4500, but I would still take the NV4500 to have the extra overdrive and more control while towing.

I know none of this will sway your decision as it sounds like you have your mind set, and to be honest the L29 is a really good motor and you will probably be happy with it (4.56 gears will help too). To answer your most recent questions, yes a 32 spline either round pattern 205 or NP241 will bolt right to the back of a NV4500, and if swapping in place of an original TH400, you can use the factory crossmember in the factory location. NP241 is probably easier as the round pattern 205 will either need a short input swap (can get from ORD) or an Advanced Adapters spacer to make work (still have to clearance the tailhousing of the NV4500 this route and get a new shift linkage to attach to the shifter). But still, the NV4500 is a really easy swap, plus, the vortec 454 and 8.1 can rev a little higher than the motors that originally came with NV4500's (cummins and 6.5's) which means you can overcome the 3/4 split easier....just food for thought I guess
 
P-pumped 6.7 cummins , NV5600 , 77.5-79 ford 60 , 11.5 AAM

If money and time meant nothing, I would say the same thing :cool1:. That combo in a square crew cab would be one of the most bitchin trucks ever though, haha

No VSS needed if going NV4500 (obviously) and honestly, swapping the NV4500 is pretty darn easy....just some parts you need to track down like the right pedal assembly, the tranny, and so forth. In my crew cab build thread I showed some pictures of swapping the NV4500 into mine. It was about as straight forward as it gets. The only part that was somewhat difficult was getting the NP205 to bolt up behind it and getting the shifter hooked up for it, but honestly, it wasn't that bad. And like I said, a 32 spline input NP241 will bolt up to it with no problems whatsoever. Just have to get the shifter hooked up, but there are some easy solutions there, or you can just get a cable shifter for the 241 (I have one on my crawler and like it).

Earlier versions of the NV4500 (92-95) still have the external bell housing and are a little easier to hook up. If you get the second gen (96+) it will be internal slave, and honestly the easiest solution there is to get the Advanced Adapters bell housing which allows you the ability to run factory 85-87 square body hydro external clutch components on the 4500, however it's pretty pricy.

I think you would be happy with the 4l80e in the long run, but as mentioned before, you will need a VSS signal which can be a pain sometimes to deal with (sometimes not) and the added cost of the wiring and e-controller component of the electronic controlled tranny.
 
I don't have to have a VSS with a manual? That is excellent news. I wanted to keep the 205 but it has a cable speedo. The NV4500 I have is a 95 version. I have the pedal assembly out of the 91 K5 but it has a vacuum assist braking whereas the crew has hydro assist. I have heard there is a difference with the two pedal assemblies. And then how does the K5 clutch system work with the NV4500. Honestly, I think the easiest thing to do would be to put the TBI 350/SM465/205 setup in it. I know I would never be happy with the power though. And towing would just be asking for trouble. But then again, 4.56s and no OD might help.
 
I don't have to have a VSS with a manual? That is excellent news. I wanted to keep the 205 but it has a cable speedo. The NV4500 I have is a 95 version. I have the pedal assembly out of the 91 K5 but it has a vacuum assist braking whereas the crew has hydro assist. I have heard there is a difference with the two pedal assemblies. And then how does the K5 clutch system work with the NV4500. Honestly, I think the easiest thing to do would be to put the TBI 350/SM465/205 setup in it. I know I would never be happy with the power though. And towing would just be asking for trouble. But then again, 4.56s and no OD might help.

Having hydraulic pedals, you should be fine with the NV4500. You can modify an SM465 bell housing to fit (like I did) or deal with the interference issues that the passenger-side slave cylinder causes with the front driveshaft. Wait...will you even have one? Maybe you'll be just fine with the stock slave cylinder. You will hafta make up a custom hydraulic line for it, but folks on here have done that already.

As for brake boost, you'll hafta deal with that either way. Do you have an automatic hydro brake pedal? If so you can cut it down to size (like I did). Or you could source an appropriate brake pedal. The difference is in the location of the pin connected to the booster (hydroboost pin is closer to pivot point). Some pedals are drilled for both pin locations, and you can simply move the pin from one hole to the other (worth looking at yours to see if it's like that).

Read through my CUCV thread for pictures of the pedals & bell housing mods.
 
Having hydraulic pedals, you should be fine with the NV4500. You can modify an SM465 bell housing to fit (like I did) or deal with the interference issues that the passenger-side slave cylinder causes with the front driveshaft. Wait...will you even have one? Maybe you'll be just fine with the stock slave cylinder. You will hafta make up a custom hydraulic line for it, but folks on here have done that already.

As for brake boost, you'll hafta deal with that either way. Do you have an automatic hydro brake pedal? If so you can cut it down to size (like I did). Or you could source an appropriate brake pedal. The difference is in the location of the pin connected to the booster (hydroboost pin is closer to pivot point). Some pedals are drilled for both pin locations, and you can simply move the pin from one hole to the other (worth looking at yours to see if it's like that).

Read through my CUCV thread for pictures of the pedals & bell housing mods.

You don't have interference issues with a external slave setup on these swaps. Mine is a 95 NV4500 as well and I've already swapped everything in for the tranny swap. Mine is still in stock form right now, and though the front shaft is close, it's not hitting nor will it hit. But a small lift would be beneficial.

Just read through my crew cab build (link in sig) about adapting the two lines together. I took some pics of how I did it....it was really easy.

Just like @campfire said, just take the auto hydroboost pedal out of the pedal assembly when you take it out, and swap it over to the clutch pedal assembly and then just cut down the pedal to look like a manual pedal and put a pad on it, then install in truck. Then you have a hydro manual pedal with a break pedal to hook up to your hydroboost brake booster...easy!
 
You don't have interference issues with a external slave setup on these swaps. Mine is a 95 NV4500 as well and I've already swapped everything in for the tranny swap. Mine is still in stock form right now, and though the front shaft is close, it's not hitting nor will it hit. But a small lift would be beneficial.

Just read through my crew cab build (link in sig) about adapting the two lines together. I took some pics of how I did it....it was really easy.

Just like @campfire said, just take the auto hydroboost pedal out of the pedal assembly when you take it out, and swap it over to the clutch pedal assembly and then just cut down the pedal to look like a manual pedal and put a pad on it, then install in truck. Then you have a hydro manual pedal with a break pedal to hook up to your hydroboost brake booster...easy!
Do you have a link to the parts to make the square hydro clutch work with the NV4500. Trying to picture in my head but pics on your thread would definitely be better...thanks. And thanks for clarifying about the external slave. That was a concern as well.
 
The '95 NV4500 is a bit of unique piece. It's still external slave (passenger side) but has the 5.whatever ratio granny gear and the bolt on shift tower. With the bolt on shift tower you can get a short throw shifter for it like I have. With the external slave you can either make a custom line and hope the drive shaft doesn't interfere or you can get the Advance Adapter bell housing with a driver side slave or even a mechanical linkage. The world is your Oyster.
 
Do you have a link to the parts to make the square hydro clutch work with the NV4500. Trying to picture in my head but pics on your thread would definitely be better...thanks. And thanks for clarifying about the external slave. That was a concern as well.

Lots of pics in my build thread about swapping the pedal assembly and also hooking up the slave/master cylinder. Link for my crew cab build in my signature below

The '95 NV4500 is a bit of unique piece. It's still external slave (passenger side) but has the 5.whatever ratio granny gear and the bolt on shift tower. With the bolt on shift tower you can get a short throw shifter for it like I have. With the external slave you can either make a custom line and hope the drive shaft doesn't interfere or you can get the Advance Adapter bell housing with a driver side slave or even a mechanical linkage. The world is your Oyster.

All true here. 95 was the hybrid year for the NV4500. The one real advantage of the AA bell housing is you can then use full factory 85-87 square clutch components...meaning you can use the master and slave cylinder with the factory hydro line off a 85-87 and it will hook up to the AA bell housing making it easier to replace clutch components, however the AA bell is a pricey unit for sure.

However you don't "have" to make a custom line if using the 95 slave cylinder. I just ran the factory 95 line up to the 87 master cylinder, and then adapter the two together with a Swagloc tube adapter (basically like a compression fitting...it was like $5 or something like that). Pic below showing how I did it....seems to work really well. The only thing that kinda sucks is if I have to replace a line for some reason...I have to repeat this procedure...but it is really cheap :thumb:

Tube adapter




And hooked up to the 87 master cylinder

 
The one real advantage of the AA bell housing is you can then use full factory 85-87 square clutch components...meaning you can use the master and slave cylinder with the factory hydro line off a 85-87 and it will hook up to the AA bell housing making it easier to replace clutch components, however the AA bell is a pricey unit for sure.

The price of the AA bell is what prompted me to use the SM465 bell housing instead. All clutch components are OEM for a hydraulic-clutch square body.

As Martin said, "I can drill a lot of holes for $400..." :haha:
 
The price of the AA bell is what prompted me to use the SM465 bell housing instead. All clutch components are OEM for a hydraulic-clutch square body.

As Martin said, "I can drill a lot of holes for $400..." :haha:

Thinking about this as an option. Seems like lining the holes up for drilling accuracy would be the key to the process. Any tips?
 
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