Plans for L32/3X00 Hybrid

[TechRod]

People use those as replacement freeze plugs, so it should work for your setup.
They're available at most auto parts stores.

[tkoforpresident]

Hell,whatever works, I don't care what it looks like

[TechRod]

Something like this...

http://www.lifeasbob.com/content/binary/Expansion_Plug_neoprene_rubber.jpg

Forgive the link, it was the first pic I found on google showing what I meant

[tkoforpresident]

scooter, you mean like one of those rubber core plugs that you screw in?

[TechRod]

I wonder if an expansion plug would work or if it would be under too much pressure and pop off?

[tkoforpresident]

Yes, that is correct. Best way to plug it would most likely be to tap the neck spot and thread in a cap fitting.

Is that something I can do myself or is it usually a machine shop kind of task?

[bszopi]

Yes, that is correct. Best way to plug it would most likely be to tap the neck spot and thread in a cap fitting.

[tkoforpresident]

I really appreciate the help you are giving me. Let me see if I can get this straight.

- The heater hose inlet that I am supposed to block off is not located in the thermostat NECK but rather behind where the thermostat itself is located (basically it comes from the LIM)

- The tube that I want to use for my heater core pretty much comes from the same spot behind the thermostat and runs (as we can see) down the middle of the LIM and exits at the rear pass. side

that sound straight?

If so, I'm confident that we have come up with the perfect plan for my setup (as far as the heater core hoses is concerned)

Question: What is a good way to "plug" the unwanted passge way?

[pocket-rocket]

The blue line in that pic goes to the coolant reservoir as a "self bleeder", if you will. Where the white line at the lower left corner of that pic is, there is a bleeder there. Normally there is another one where that blue line attaches to the t-stat housing (where that radiator hose is hooked onto on the right), but in this case, there is a tube with no restriction headed to a port on the coolant tank, so the system is constantly burping air out and into the tank. If you were to follow that white line under the radiator hose and under the TB, that is one of the heater core lines. The other one comes off the rear of the t-stat housing (which is just under the TB at the end opposite of the radiator hose on that t-stat housing and has a tube coming out of it to hook to the heater core. One LIM setup has the tube press in (with an o-ring on it) and is held into place with a stud and nut attached to the rear head. The other style uses a type of quick connect setup (which is where you get the talk of people threading the hole for the tube).



If you look at the left side of the manifold (thanks for the nice big pic, Ben ), you see where the tube down the center hooks into. That is where the t-stat lives. Coming off the bottom of that is where the 2nd heater hose comes from that I was suggesting you plug up, then you would use the tube that goes down the center to eliminate the hose/line that you mentioned earlier and hook it in at the rear of the engine instead of the front. This is the best I can figure by going by pics and not having an F body and a 3x00 in front of me. I'm also tired, but I hope that this helps and would work.

[tkoforpresident]

Just to verify, this is a perfect picture to show what I'm thinking now.

As you can see, the BLUE line is the coolant tube that runs (i think) from the thermostat housing to the 2nd heater core inlet. By plugging that hole (or buying a TCE thermostat housing) I hope, that I can entirely disregard that pipe.

seems to make sense to me now.

[tkoforpresident]

There is another one that comes out below the TB from the t-stat housing too. That would be the 2nd one. Really I imagine you could pull that tube out and plug the hole and run a single line since they both come from behind the t-stat anyways. Actually, the more I think of it, I would plug the one coming off the side of the t-stat housing and use that tube. That would remove that long metal line from your bay and clean it up a little. Then just run a molded flex hose from that tube to the core since most likely it would only need a 90 bend in it.

thank you so much!

I think I understand now. That "tube" you are referring to is the one that runs along the front (in a fwd application) valve cover! I was wondering what the heck that was.

Question: If I purchased a TCE forward facing thermostat housing will that "eliminate" the need to even "plug" that hole since I don't believe that outlet is even present on the TCE housing? A forward facing housing would also allow me to reuse my old upper radiator hose.

[pocket-rocket]

There is another one that comes out below the TB from the t-stat housing too. That would be the 2nd one. Really I imagine you could pull that tube out and plug the hole and run a single line since they both come from behind the t-stat anyways. Actually, the more I think of it, I would plug the one coming off the side of the t-stat housing and use that tube. That would remove that long metal line from your bay and clean it up a little. Then just run a molded flex hose from that tube to the core since most likely it would only need a 90 bend in it.

[tkoforpresident]

NO but seriously, I'm freaking out. What does John mean by 2 heater core outlets on the FWD manifolds?

The only one that I saw was that metal tube that exits at the rear pass. side.

I need to figure out how to run these hoses

I have got to be correct though about the heater core hose running to the water pump... and that it should not under any condition be removed.

[tkoforpresident]

now that I think about it the hose that I highlighted in RED earlier is the one going to the water pump so that can't be altered at all.

It's the hose NEXT to it that would normally run into the 3.4 LIM that I will have to alter since there is no fitting for it on the 3500 LIM

is this correct?

If that's so then there shouldn't be a problem. I will just route the one hose normally to the waterpump and the other one (the one that used to go into the 3.4 LIM) to the NEW outlet coming out of the rear of the 3500 LIM

I think that makes sense...

[tkoforpresident]

You will end up with an extra heater core hose on your engine since there's one on the water pump for the 3.4, and in two places on the FWD manifolds.

Throttle cable can be pirated from a GM truck and is a direct fit (have part number at shop).

The TB sensors are a direct swap, they are the same.

The t-stat needs to be the FWD unit.

You can boost the 11.5:1 SCR motor, just be aware that the tuning has to be spot on.

Pacesetters work, you just need to slot the top holes of the flanges and the roofs will match the headers just fine, the 1.5" primaries being round will just barely interrupt the "square" corners on the bottom of the "D" shaped exhaust ports of the FWD heads. GM raised the roofs, the bottom mounting holes stayed in the same location.

John if you could get me that throttle cable part # I would be very appreciative. It would save me a lot of trouble.

Also, I'm not entirely sure I understand what you mean by my having "an extra heater core hose"