360 to small block chevy

[J20man]

I have a J4000 with a amc360 to an adaptor plate to a GM turbo 400...
can I not loose the adaptor plate and go to a small block chevy? and or is a big block out of the question if I have it.
I can do the work, I just want to know about adaptability, if it can mate up, would the master cylinder be in the way? etc.

[mattmopar440]

there shouldn't be an adapter plate the th400 has a custom bellhousing for AMC engines

[J20man]

nope...this one does, I put the motor in myself and there is an adaptor plate for it from the gm 400 tranny

[CHICOWAGGY]

Actually, you should have an adapter plate, however the pattern on the turbo 400 is for a Buick Nailhead, so no you cannot bolt up a chevy engine (by the way the big block and small block chevys have the same pattern). You can get a chevy turbo 400 swap output shafts and run your transfer case tho.

[KaiserMan]

The 73 and older Jeeps used adapters to mate various motors to the TH400.

BUT, it is a Buick nailhead pattern TH400, so you can't bolt up a Chevy motor to it.

[KaiserMan]

Actually, you should have an adapter plate, however the pattern on the turbo 400 is for a Buick Nailhead, so no you cannot bolt up a chevy engine (by the way the big block and small block chevys have the same pattern). You can get a chevy turbo 400 swap output shafts and run your transfer case tho.
You beat me.

[mattmopar440]

should bolt up once you make new engine mounts and gauges and wiring

[J20man]

ya your right, thats what they were saying in other threads...crap...now I need to do some thinking...

[CHICOWAGGY]

You beat me.

Barely:thumbsup:

[J20man]

Barely:thumbsup:

Ok...just made a phone call and got some info here...after calling Advance Adaptors, for my year if I want a gm motor one of the ways to go is to install a turbo 400 that mates right to a gm motor and for around $600 they will provide an adaptor plate that will accept the dana 20 transfer case and then a maybe a slight change to the shafts then it's done.

[J20man]

You beat me.
thanks KaiserMan:)

[J20man]

thanks everyone!!

[eyotajeeper]

The easiest way(motor to trans wise) is to get a th400 chevy trans. The ones I have used you are the right length to just pull the tailhousing cone(6 bolts) off and bolt on the stock adapter from behind your stock trans.

[Cecil14]

You can get a chevy turbo 400 swap output shafts and run your transfer case tho.

THAT is the correct way to do it. Giving AA $600 is not. lol Spend that money on the rebuild kit you'll need when you tear the trannies apart. ;)


aa

[mdill]

If it was me (which I understand it is not) and you are totaly sold on the small block or big block chey.
I would find a Chevy TH400 (not sure if there was a K series or not, if so that would be desirable but not a huge deal, if you don't beat it hard) pretty much any Chevy or dual pattern TH400, core.
Stuff your current guts in it, (no new adapters ...) set the tranny transfer case in the same exact spot they are now (no new drivelines, linkages ..) then install the motor mounts to match that location.

Mike D.

Ok...just made a phone call and got some info here...after calling Advance Adaptors, for my year if I want a gm motor one of the ways to go is to install a turbo 400 that mates right to a gm motor and for around $600 they will provide an adaptor plate that will accept the dana 20 transfer case and then a maybe a slight change to the shafts then it's done.

[eyotajeeper]

Just to clarify, a 2wd chevy th400 will bolt directly to your tc after you pull the cone off the tailshaft. No swapping the guts is required, unless you want to overhaul it.

I'm sure AA would sell you the adapter that you already have for $400 plus!:D

[CHICOWAGGY]

Just to clarify, a 2wd chevy th400 will bolt directly to your tc after you pull the cone off the tailshaft. No swapping the guts is required, unless you want to overhaul it.

I'm sure AA would sell you the adapter that you already have for $400 plus!:D

You would still have to swap output shafts.

[ozziewynot]

A very simple solution might be the Chevy to Buick-Olds-Pontiac bell housing adapter offerred by Trans Dapt for $90 . I've used the opposite adapter plate for Pontiac to Chevy 700R4 . Beautiful and simple .
I would guess the main consideration would be the spacers on the torque converter to flex plate . If it works for you , you just saved a ton of money and labor .

[CHICOWAGGY]

A very simple solution might be the Chevy to Buick-Olds-Pontiac bell housing adapter offerred by Trans Dapt for $90 . I've used the opposite adapter plate for Pontiac to Chevy 700R4 . Beautiful and simple .
I would guess the main consideration would be the spacers on the torque converter to flex plate . If it works for you , you just saved a ton of money and labor .

It won't work because the BOP pattern is different than the Buick Nailhead pattern.

[ozziewynot]

Bummer ........... didn't know GM had so many patterns . But , kind of makes me wonder , have any of the hot rod parts suppliers come up with one ( nail head pattern to chevy ) or produced one in the past?

[1983 j10]

You would still have to swap output shafts.

the 2wd and 4wd th400's use the same output shaft just different tail housings.

[CHICOWAGGY]

the 2wd and 4wd th400's use the same output shaft just different tail housings.

If you want to run your transfer case you would still have to swap output shafts im pretty sure.

[1983 j10]

if its the same spline count it should work just fine.

[CHICOWAGGY]

if its the same spline count it should work just fine.

If, but I'm pretty sure it isn't, especially if its a quadratrac!

[Cecil14]

QT uses a unique-QT-only output shaft. Not sure on the D20 shaft...it may be the same as a standard TH400 shaft...no idea.


aa

[eyotajeeper]

The chevy th400 2wd trans will work , I've done it myself, no gutting the trans, spline count is the same!

A th400 that is set up for a quadratrac is the wrong spline count(10 I believe) but as far as I know only came with AMC pattern on the front(block) end!

[CHICOWAGGY]

The chevy th400 2wd trans will work , I've done it myself, no gutting the trans, spline count is the same!

A th400 that is set up for a quadratrac is the wrong spline count(10 I believe) but as far as I know only came with AMC pattern on the front(block) end!

Right you can use a 2wd trans, I understand that, but I don't think you can bolt a Jeep Dana 20 to it without swaping output shafts and I definitly know that you can't bolt a QT to it without swaping shafts.

[eyotajeeper]

A dana 20 with the stock adapter that goes to the original nailhead th400;)