Dana 20...TH400 adapter or not?

[porkchop]

Yes this I know. The AMC TH400 is slightly tilted to the passengers side. Jeep did this to run the QT.

[porkchop]

I finally remembered and went out and got a picture of the bellhousing of the TH400 on the 70 wag. Here it is.

It also has a really deep pan, deeper than mine, that has the standard GM writing on it.

[J20 project]

PC, It's Chevy or BOP allright, but original??
Not a chance in my book. Someone swapped it out and allready did the conversion to a chevy case it looks to be. J20

[Crazy_Jeepman]

That looks to be a Chevy Bolt patern NOT BOP. What exactly are we trying to see and do here, somehow I am lost on this. If you need a Pic of the BOP transmision and BOP to Nailhead adapter I can do that for you. I would also add there is NO crank spacer for the converter on the Nailhead patern transmision, . I have two Nailhead Patern transmisions and two BOP to Nailhead adapters, 4 TH400 to D20 Adapters, and I can get the AMC to Nailhead adapter as well. So if I could just understand what in the name of FSJ we are trying to do here, I can Help I am sure In Fact I will go take some Pics of the Nailhead bolt patern and adapter and post them so we can get a good idea as to what it all looks like I have a feeling not many have seen this setup before.

[Hump]

As the originator of the topic, I need to know exactly all the parts I will need to go from a 401 to a th400/dana 20 combo. I have the dana 20 and adapter to the th400. I am also in the process of purchasing a th400 with the tranny to block adapter as well as the flexplate spacer.

So I think I have everything figured out from the tranny back. I now will have the correct output shaft. Now I need to know what it takes to bolt up the nailhead tranny to my amc 401.

[Crazy_Jeepman]

Here is a BIG PIC of the adapters and Nailhead Patern. BOP and Nailhead bolt paterns and Adapters!!!
If you notice the Nailhead TH400 without the Adapter the Torque Converter sticks out from the belhousing with the adapter on....it is flush, this being the reason the nonexistent Crank spacer does not exist. Next is the Bolt patern, until AMC cased the TH400 with their own case, ALL previous TH400 were Nailhead bolt patern, and would not EVER BOLT up to any engine Jeep ever used without the adapter ring for the specific engine used. Such as the AMC 327, Buick 350, and AMC 360, adapter rings were needed for each of these engines, each being different, 3 different adapters were used. There is the Tailshaft with the O ring seal and Spud shaft to hook up the D20 to the TH400. Hope this helps everyone that is confused on this subject

[ August 01, 2002, 09:53 AM: Message edited by: Crazy_Jeepman ]

[Hump]

Thanks CJM! So basically I just need the correct adapter from tranny to block and i'm done. That's good news.

[porkchop]

The picture I posted is from a 70 wag. We were trying to figure out if it is original or not. The guy that the wag came from says that it is. I don't know for sure.

[Crazy_Jeepman]

Porkchop it is not original. That is a Chevy bolt patern, I have one of them as well.

[porkchop]

Originally posted by Hump:
Thanks CJM! So basically I just need the correct adapter from tranny to block and i'm done. That's good news.

Good news but they are hard to come by. Not to many of them left out there as far as I know. The guy that the 70 came from still has the adapter for the 350 to include the original 350.

[Bob Barry]

Originally posted by porkchop:
I finally remembered and went out and got a picture of the bellhousing of the TH400 on the 70 wag. Here it is.

It also has a really deep pan, deeper than mine, that has the standard GM writing on it.

IIRC, a Chevy-pattern would have five-bolts; the bottom four shared with the BOP pattern, and a single top bolt, rather than two top bolts for the BOP pattern. The universal-case TH350's and the like have seven bolts, with the top bolts for both the Chevy and the BOP patterns.

That torque-converter looks like it's sticking out pretty far. Comparing that pattern to the BOP-nailhead adapter pictures posted, I'd say Porkchop has a nailhead-pattern tranny in that '70.

[Crazy_Jeepman]

flexplate spacer
Sure would like to see a Pic of that! Or is it an AMC thing? I have never pulled the one I have apart, but I know the Buick there is no spacer.

[ August 01, 2002, 10:08 AM: Message edited by: Crazy_Jeepman ]

[porkchop]

Originally posted by Crazy_Jeepman:
Porkchop it is not original. That is a Chevy bolt patern, I have one of them as well.

Hmmmmm, I wonder why he said it is. He has the adapter for it and everything. I will have to get a hold of him and see what's up. I don't know for sure, I am learning on this. Thanks for all the help. I am sure Hump is glade as well .

[porkchop]

So is it original, Bob? This is getting to be confusing .

[Crazy_Jeepman]

Nothing confuseing really. I will explain it clearer this time. Jeep NEVER EVER EVER used a BOP Patern Transmision in ANY Jeep........ It was a Buick NAILHEAD only bolt patern. The Only way Jeep was able to hook up the Nail Head transmision was through an adapter ring Like I have pictured here, a different adapter was used for each different bolt patern used. AMC 327, and BOP for the Buick 350, and the later standardized AMC bolt patern. 3 different adapters in all. NAILHEAD Adapter
UMMM This look familiar??? I pulled a 454 from a Chevy Pick up this TH400 was behind it. Looks like your pic! Chevy Bolt patern