No way this is right?

[78SierraGrandeTX]

A 4 speed or 3 speed? I'm just curious now.

Per the sticker on the glove box, MX1 automatic transmission, so a 3 speed I believe

 

[Bextreme04]

Per the sticker on the glove box, MX1 automatic transmission, so a 3 speed I believe

Well, considering how much other things have been changed, I don't think I would trust the sticker. If they took the whole drivetrain when they got the TBI motor, they might have swapped to a 700R4. It wouldn't have a 4L60E or 4L80E since you don't have the wiring or computer to support that. Take a picture of the trans pan and someone should be able to ID it.

 

[78SierraGrandeTX]

.

 

[78SierraGrandeTX]

Well, considering how much other things have been changed, I don't think I would trust the sticker. If they took the whole drivetrain when they got the TBI motor, they might have swapped to a 700R4. It wouldn't have a 4L60E or 4L80E since you don't have the wiring or computer to support that. Take a picture of the trans pan and someone should be able to ID it.

Good idea I’ll take a look at it tonight

 

[Vbb199]

That's what I was getting at.
Since it's a tbi motor, I'm gonna take a guess to say there's probably a 700r4 behind it (4 speed automatic)

 

[AuroraGirl]

Yeah PCV definitely needs rework. One side should have a PCV valve at the front or back of engine with the other valve cover having a breather at the opposite side of the pcv. Like my PCV is in the driver side front of engine(Front being by belt drive), then my breather is on the passenger rear(rear by the firewall). Of course, the PCV needs to be hooked up to the carburetor. Usually the front of the base of the carburetor is the inlet.

 

[78SierraGrandeTX]

That's what I was getting at.
Since it's a tbi motor, I'm gonna take a guess to say there's probably a 700r4 behind it (4 speed automatic)

Looks like is is going to be a TH 400.

It has 13 bolts and the shape seems to resemble the TH400 shape. Do you guys agree?

The pictures don’t really do any justice...

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[78C10BigTen]

Looks like is is going to be a TH 400.

It has 13 bolts and the shape seems to resemble the TH400 shape. Do you guys agree?

The pictures don’t really do any justice...

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It appears to be... im not 100% but i can sure tell you its not a th350.

 

[Vbb199]

That is a 400 I do believe.

Guess the PO just left the trans and put a tbi motor in.

 

[gotyourgoat]

It appears to be... im not 100% but i can sure tell you its not a th350.

Yep.

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That 'gap' on the mating of the carb/intake doesn't bother me, many are made to mate to multiple carb to intake combos.
There are a couple visible vacuum issues in those pics though, ie open lines off valve cover, zip tie holding something not made for vacuum cap.

 

[Raybo135]

I personally think they have the Valve covers on the wrong side. The breather hose should be on the rear of the passenger side and the PCV should be on the from of the driver's side cover. With the original style air filter, there is a connection for the hose on the passenger side to go up into the side of the air filter. And the PCV would go into the carburetor on the front. As you can see by pics of my original 400, the PCV is on the Driver's side and the Oil Filler is on the Passenger side.And the Breather hose would attach to the Air Cleaner on the side.

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[78SierraGrandeTX]

I personally think they have the Valve covers on the wrong side. The breather hose should be on the rear of the passenger side and the PCV should be on the from of the driver's side cover. With the original style air filter, there is a connection for the hose on the passenger side to go up into the bottom of the air filter. And the PCV would go into the carburetor on the front.

I thought about pulling the covers off to put a fresh coat of paint and cleaning off all of the old gasket sealant that is around. Before I do that I will look into this issue some more.

Thank you for your input!

 

[89GMCJimmy]

It depends are you trying to set it up as the 1978 or set it up as the newer engine was stock?

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[89GMCJimmy]

It depends are you trying to set it up as the 1978 or set it up as the newer engine was stock?

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This is a stock 1989 350 TBI set up, PCV is pass side going into front of TB. Drive side has vent going into riser between TB and air cleaner.

 

[89GMCJimmy]

I'm not positive but I believe your Brake Master Cylinder is off a newer vehicle too. My 78' Jimmy had an iron reservoir.