205 wanted

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bucket

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I could be wrong but my understanding is that you could switch out the input shaft with the one you need and if someone has a figure 8 trans adapter to measure I could measure mine and we could verify.

That's right, you can do that in many cases. I think what makes the round pattern case more desirable now is modern trans swaps like the popular NV4500. The trans has the round pattern adapter built into it, so a round pattern case is the only thing that will bolt up.
 

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That's right, you can do that in many cases. I think what makes the round pattern case more desirable now is modern trans swaps like the popular NV4500. The trans has the round pattern adapter built into it, so a round pattern case is the only thing that will bolt up.
It defiantly would be if there was availability of a 6 bolt round pattern case. I have owned 17 squares and have worked on over 50 and looked under hundreds of them and have only ever seen one 6 bolt round pattern GM np205 and that's the one in my jimmy right now. I live just down the road from Advanced Adapter so when I got this 205 I went by there to see if they made an OEM adapter because on my first 205 I owned and installed on my green and gold blazer I broke the weak OEM adapter (figure8) in the middle of now where and had to use ratchet straps to hold it together so I could get back to a road where I could load it on a trailer and hall it home. I live just down the road from Advanced Adapter so when I got this 205 I went by there to see if they made an OEM adapter. The gentlemen that helped me said that there wasn't enough demand for that adapter because GM didn't make it for very many years. I was hoping I could source a replacement just in case I broke this one but no such luck. I'm not trying to stir the pot I'm only trying to let Jr1940 no that there are other options that in my opinion might be better considering the availability of figure 8 205's and advanced adapters makes an adapter for most transmissions for them. this subject is something I've been doing a lot of research on lately because I want to put an ORD magnum underdrive on my Jimmy. I will have to buy another figure 8 205 or have my dodge one milled out for the big bearing because ORD doesn't make one for the 6 bolt round GM 205. I hope this doesn't make me come off as a know it all because in no way do I think I have all the answers, and if someone could point me in the right direction I would obliged.
 

HOTFOOT

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I could be wrong but my understanding is that you could switch out the input shaft with the one you need and if someone has a figure 8 trans adapter to measure I could measure mine and we could verify.
My 80 3500 400/205 is 4”
 

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78C10BigTen

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I also have a figure 8 i could measure if needed, mine was attatched to an sm465.
 

Vbb199

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Did not know the round pattern 205's are so highly sought after.... last time I checked out the local yard's "t case and transmission" school busses (literal gutted busses lined with drive train components), I recall spotting a couple 205's, but passenger drop doesn't interest me
 

AuroraGirl

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I also have a figure 8 i could measure if needed, mine was attatched to an sm465.
i too have this, in a 77 and 80 the only difference is the height of the adapter off the crossmemeber, the 77 is taller the 80 was shorter but the 80 has a slip yoke and 1 piece shaft vs 77 is still a fixed output and 2 piece so the height may be for the driveshaft idk.

heres pics of a 77 for the ***** and giggles because the part number is there
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Red 1

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alright I finally measured the adapter it is 4”. I have it behind a 2wd 4l80e with a spacer. I trimmed the input and output shaft to make it fit.
 

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