Sm465 to figure 8 np205

[iwaxmyjimmy]

Ok I've been researching this for 2 days now. Currently I have a 10 spline sm465/205 combo. I can get my hands on a 32 spline sm465 but it's got a 208 behind it. If I find a short 32 spline input 205 figure 8 from a earlier model th400 can I used the figure 8 adapter off of my 10 spline sm465 work? Im pretty sure I can find a figure 8 32 spline 205 at a friends house.

 

[sweetk30]

465 with 32 spline should be round adaptor .

needs a long input gear and can modify the 208 adaptor to clear the shift rail but wont have a shifter bolt boss .

why the switch for the same tranny ?

 

[iwaxmyjimmy]

I would like to build a NWF econobox to put in front of the 205 and the 32 splined stuff just sounds like it would hold up better. I'm tracking the sm465 will have a round pattern adapter but with the long shaft and the regular 465 figure 8 pattern adapter it should fit a th400 figure 8, 205 though right? Ill end up putting cable shifters in it. So that takes care of any issues with that. I already have a clocking ring for the figure 8 too.

 

[truck-oholic]

You are talking about two different things here. If you are putting the econo box in front of the 205 then the round pattern adapter from the 32 spline sm465 is what you need. You would have to ask NWF if their box can adapt to a figure 8 205 but I doubt it. I believe you would have to run a round pattern 205 behind the econobox but who knows, you may be able to drill and tap the face of the 205 to work with the econobox like I drilled and tapped the face of a 203 to go behind my round pattern SM465 adapter.

Now, if you are just wanting to run the 205 directly behind the sm465 then I don't know off hand about the adapting options but I am pretty sure your 10 spline adapter will be much too short and you will have too much sm465 output sticking out. I think some people have cut that output shaft down before to make shorter length units and use non-oe adapters like you are wanting to do. If it's easy enough to get the stuff from your buddy then just try it out and report back.

Not the cheapest option but you could also just get a round pattern 32 spline 205 and use the stock 32 spline sm465 adapter. Those versions are usually kind of high dollar. Maybe $500-600 for a good unit

 

[iwaxmyjimmy]

You are talking about two different things here. If you are putting the econo box in front of the 205 then the round pattern adapter from the 32 spline sm465 is what you need. You would have to ask NWF if their box can adapt to a figure 8 205 but I doubt it. I believe you would have to run a round pattern 205 behind the econobox but who knows, you may be able to drill and tap the face of the 205 to work with the econobox like I drilled and tapped the face of a 203 to go behind my round pattern SM465 adapter.

Now, if you are just wanting to run the 205 directly behind the sm465 then I don't know off hand about the adapting options but I am pretty sure your 10 spline adapter will be much too short and you will have too much sm465 output sticking out. I think some people have cut that output shaft down before to make shorter length units and use non-oe adapters like you are wanting to do. If it's easy enough to get the stuff from your buddy then just try it out and report back.

Not the cheapest option but you could also just get a round pattern 32 spline 205 and use the stock 32 spline sm465 adapter. Those versions are usually kind of high dollar. Maybe $500-600 for a good unit

He's got like a 4x4 junkyard and if I can find what I need, I'll trade him some parts, my 10 spline stuff and a 14 bolt, to get the parts I need. Thought I had a 465/205 round pattern but the guy realized what he had and decided to keep it, was going to be a steal at $350. I need to go back out there because I think I saw a 454/465/? Combo last night when I was out there. It was an '85 k1500 so I know that's not the factory drivetrain. im only going to run 4.10s in the axles and leave all the gearing in the t-case.

 

[skunked]

You are talking about two different things here. If you are putting the econo box in front of the 205 then the round pattern adapter from the 32 spline sm465 is what you need. You would have to ask NWF if their box can adapt to a figure 8 205 but I doubt it. I believe you would have to run a round pattern 205 behind the econobox but who knows, you may be able to drill and tap the face of the 205 to work with the econobox like I drilled and tapped the face of a 203 to go behind my round pattern SM465 adapter.

Not sure if you can drill it or not however NWF sells an adapter that goes from the eco box to the figure 8 np205. I've been leaning toward this setup for the better gearing......

http://www.northwestfab.com/GM-NP205-Fig8-to-GM-6-Bolt-Round-Adapter_p_18.html

 

[iwaxmyjimmy]

Not sure if you can drill it or not however NWF sells an adapter that goes from the eco box to the figure 8 np205. I've been leaning toward this setup for the better gearing......

http://www.northwestfab.com/GM-NP205-Fig8-to-GM-6-Bolt-Round-Adapter_p_18.html

Yeah I was tracking that too. Finding a figure 8, 32 spline input 205 won't be as hard for me and is the route I'm leaning towards, but was trying to see if I could run it without the range box for right now then add the range box later.

 

[iwaxmyjimmy]

I just found what I needed, ORD makes an adapter for $125. I have a feeling it's the same thing as the NWF adapter

 

[wombat]

The adapter that ORD makes is not the same that NWF makes. The adapter ORD makes is thicker and is what you need to put your figure 8 205 in place of a round pattern 208. But it is to thick to go between the eco box and 205, you would have to buy NWF's adapter. This is the exact same setup I am piecing together for my truck and I have already talked to both companies. ORD also make a shorter output shaft and factory style but shorter adapter to go on your 465 to bolt the 205 up. There was no real benefit in that for what I wanted though.

 

[iwaxmyjimmy]

The adapter that ORD makes is not the same that NWF makes. The adapter ORD makes is thicker and is what you need to put your figure 8 205 in place of a round pattern 208. But it is to thick to go between the eco box and 205, you would have to buy NWF's adapter. This is the exact same setup I am piecing together for my truck and I have already talked to both companies. ORD also make a shorter output shaft and factory style but shorter adapter to go on your 465 to bolt the 205 up. There was no real benefit in that for what I wanted though.

Damn, was really hoping I could get away with only buying one adapter. Kinda sucks but you can drill and tap the face of a figure 8 to change it to a round pattern right? Just need that longer input? This is starting to seem like a polished turd lol

 

[Hogback Fabrication]

Damn, was really hoping I could get away with only buying one adapter. Kinda sucks but you can drill and tap the face of a figure 8 to change it to a round pattern right? Just need that longer input? This is starting to seem like a polished turd lol

Nope. You can drill/tap the figure 8 pattern on a round case but you can't go the other way, the casting doesn't leave material to drill/tap the round pattern on the figure 8 case. Otherwise nobody would ever care about the round pattern cases.

 

[truck-oholic]

Why not just go ahead and put the eco box in now and be done with it? It would save you time and money later on by not having to buy another adapter or redo crossmembers & driveshafts!

 

[iwaxmyjimmy]

Why not just go ahead and put the eco box in now and be done with it? It would save you time and money later on by not having to buy another adapter or redo crossmembers & driveshafts!

funds mainly but I build things in stages. Wanted to get it running and driving then go through my next rounds of mods, flat belly and doubler next winter so I could wheel it through the summer atleast. Right now I could run my 10 spline stuff as is, and I'll have to build a new crossmember and redo the trans tunnel to fit everything like I want to anyway. It's already been sidelined for the past 5 years because I was stationed on the opposite side of the country.

 

[iwaxmyjimmy]

Nope. You can drill/tap the figure 8 pattern on a round case but you can't go the other way, the casting doesn't leave material to drill/tap the round pattern on the figure 8 case. Otherwise nobody would ever care about the round pattern cases.

Thanks I knew it was something like that. I'll probably just end up doing a round pattern 32 spline 465 and the ORD adapter for the time being. Then I might end up just running the ORD crawl box and sell the ORD adapter to someone. Really liked the price of the NWF DIY one.

 

[truck-oholic]

What I am trying to tell you is that if you spend $800 now you can easily save at least $500 later. Building in stages, while sometimes convenient or easier on the wallet NOW, always winds up being more expensive LATER. The first 4x4 I built I did in stages and it is unbelievable the amount of money I sunk into that thing just to keep changing it a couple months later. If you are on a budget, spend wisely, buy USED whenever possible, and make smart decisions that will keep total long term cost down. Just my $.02 that cost me more like $20k, but you are obviously free to do what you will

 

[iwaxmyjimmy]

What I am trying to tell you is that if you spend $800 now you can easily save at least $500 later. Building in stages, while sometimes convenient or easier on the wallet NOW, always winds up being more expensive LATER. The first 4x4 I built I did in stages and it is unbelievable the amount of money I sunk into that thing just to keep changing it a couple months later. If you are on a budget, spend wisely, buy USED whenever possible, and make smart decisions that will keep total long term cost down. Just my $.02 that cost me more like $20k, but you are obviously free to do what you will

I'm all for doing it right the first time and not redoing anything, but I also know don't keep a project torn apart for too long and adding too much work, or you wont enjoy it. If I end up losing $125 for using the ORD adapter, which I'm pretty sure will be easy to resell for 2/3ths of what I buy it for, then its worth not getting burnt out on the project and enjoying my K5. I'm curious to the thickness of the ORD adapter and I'm hoping with running the clocking ring I will still have enough spline engagement considering its about 3/8" thick.

Now If run a crawl box from ORD all I'll have to do is bolt the magnum box between the two. When I do that I'll go flatbelly and rebuild the floor, which I'll need to redo my rear drive shaft unless I get a long enough slip spline to handle it. The front should be just fine since Ill probably just run square tubing for it. Now if I went with the NWF DIY crawl box I could run the round pattern t-case adapter housing, probably get a spacer machined to get the right amount of spline engagement for fairly cheap, and Ill have to buy a $175 adapter. Again I can probably resell that ORD figure 8 adapter and get a good amount of money back out of it. So I'm not really seeing where you're claiming its going to save me $500 by spending $800 now. And it would be more less about $1400 for the DIY NWF crawl box with shifters and the adapter I need. I might lose $50 from reselling the adapter and have to change the length of my rear driveshaft. I can wait a year or so and enjoy my K5 and waste $100 its not that bad.

I'm not being an asshole and trying to act like I have all the answers but this is how I've rationalized it. My time spent driving my K5 and enjoying it on 1 tons and a sorta crappy crawl ratio till I flatbelly it and add the crawl box is ok wasting $50-$100.

 

[truck-oholic]

A SINGLE good quality custom shop-built driveshaft will run you about $500. If you had two of those it would be $1,000. If you were just shortening or lengthening stock driveshafts then you are back to $300-$500 for two and you still have to revisit your crossmembers and skid plates. I've run square tube driveshafts front AND rear on a trail only truck and it is not something I plan on doing again or really recommend.

Something else you are not thinking about is that whenever you change drivetrain length or height (i.e. clocking cases) you are not only changing driveshaft lengths but also operating angles meaning you will have to readjust your pinion angles and/or go to a CV joint for more operating angle. It's not just a matter of having enough slip to cover the difference.

Let me back up for a minute and ask if this is a street driven truck or a trail only truck? I assumed, maybe wrongly so, that this was a street driven truck that also did some wheeling.

 

[iwaxmyjimmy]

A SINGLE good quality custom shop-built driveshaft will run you about $500. If you had two of those it would be $1,000. If you were just shortening or lengthening stock driveshafts then you are back to $300-$500 for two and you still have to revisit your crossmembers and skid plates. I've run square tube driveshafts front AND rear on a trail only truck and it is not something I plan on doing again or really recommend.

Something else you are not thinking about is that whenever you change drivetrain length or height (i.e. clocking cases) you are not only changing driveshaft lengths but also operating angles meaning you will have to readjust your pinion angles and/or go to a CV joint for more operating angle. It's not just a matter of having enough slip to cover the difference.

Let me back up for a minute and ask if this is a street driven truck or a trail only truck? I assumed, maybe wrongly so, that this was a street driven truck that also did some wheeling.

It'll mainly be trail but I think cruising for an hr at 50-60 on the highway it should be just fine. I'm going to run 1410 joints at both ends on both front and rear shafts. Friend of a friend has a flat belly with just a 205 in his k5 running 1410 joints and 56s up front and has no problems at all with binding. I'm also going to run slider boxes up front to keep the the pinion angle more in check during droop with 52s, out back just a shackle flip and 56s. So a relatively low lift height will help a lot with my angles too. Running just single joints instead of a 1310 or 1350 CV drops the cost significantly. I'm looking at $350ish for the rear shaft, which like I stated before ill use enough slip spline where after I flat belly it, I should be fine since the rear might change only inch or two at the most. The front will be a little more tricky finding a happy medium but at the same time I have no problem with running a square tube front shaft.

edit: added a picture for you to know I'm not just talking out of my ass.

 

[truck-oholic]

Sounds good

 

[82355]

If you are going to do it in stages, run the SM465/NP208 while you gather the parts for the doubler, or just keep what you have until you are ready for the entire trannsmission/doubler setup at once.

Otherwise you are just wasting money.

Martin