Preparation for heads, uim, camshaft and downpipe

[IsaacHayes]

Yeah and if using the 3400 TB on the 3500 with adapter this is how you do it:

[skinrock]

Yeah and if using the 3400 TB on the 3500 with adapter this is how you do it:

had it edit the link, I'm logged in on www.60degreev6.com, which doesn't carry over to just 60degreev6.com, lol.

[skinrock]

well I gotta admin, the pic is a little confusing, are you saying it's gonna maybe take some custom work to use the stock TB, since I have to use a 3500 adapter with my LIM?

[IsaacHayes]

lol, well at least you figured out how to see it. I'll edit it to www.

Well if you use the 3500 TB adapter, it doesn't have a square notch for the IAC flow. The older 3100 small ports didn't either but later the 3400 plenums had a notch so they changed the TB. I don't know why they changed.

But yes cut it like shown if yours isn't open. My small port 3100 52mm TB was open and would work, but the 3400 one I had required the modification. Once modified it will work fine on a stock 3400 plenum too so it doesn't make anything non-reversible.

If you use a 3400 plenum, no modifications needed. If you use the 3500 plenum then you need the TB adapter and the above mod among other little things. The 3500 plenum is a better design than the 3400 one. But if you don't want to mess with that stuff then a 3400 plenum will bolt to the 3500 lower just fine.

[skinrock]

Oh, so the plenum actually bolts into the LIM? I thought it was part of it...

If the 3400 "plenum" bolts onto the 3500, I'll just do that for now. I eventually want to get the 65 mm TB, and then I guess I'll get the adapter then...but I'm tight on cash till next week, and after that, I probably won't be able to get parts in time for the week of 4th of July, when I'm on vacation.

Anyways, you also said "the above mod and other little things". Is that in reference to using the adapter plate, or do you mean little things in general with the entire swap?

I was kinda under the impression that as long as I had the heads, LIM, head bolts (have), and gasket kit (ordering tomorrow), and some silicon, I'd have everything I need.

I only have one weekend, one shot at this...it's gotta go right, lol. I mean I have another ride available if necessary, but I don't wanna go there...

[gectek]

yah the 3400 upper manifold will bolt right to the 3500 lower, andu can use everything else u have to make it work. just make sure the lower intake gaskets u use will fit the LIMport, and that the uppergasket is not in the way whenu put it on,u can cut a little off to fit. thats it

[skinrock]

Well, from what I understand, the gasket kit that I'm ordering is for the 3500...so it should work I assume:

http://www.gmpartsdirect.com/results.cfm?singlepart=1&partnumber=12594816

[IsaacHayes]

The "UIM" or "plenum" unbolts and lifts off thats how you get to the injectors and the other bolts for the LIM.

You will need LIM gasket for the 3500 not the 3400.

For the other 3500 plenum issues see my thread here. Not all will apply to your car like the vacuum for transmission (yours doesn't need it). Nor will the stuff about the lower intake. But MAP sensor and vacuum for FPR etc little things apply.

[gectek]

well themanifold vacuum ports are ontheUIM soyou dont have to worry about anything as long as u use the 3400 upper intake...the only thing i know that u have to do is to tap a hole for the coolant temp sensor, unless you can extend ur harness...is that right isaac...and that is it

[IsaacHayes]

Check 3400-modified's threads for info on that. He swapped heads but I think he ended up modifying the coolant sensor to fit the head of the 3500 lol. I've heard of others taping the coolant neck to put the sensor there too. I'm not sure on the details but yeah it's different.

[skinrock]

I'm not getting any results for that name, do you have the exact spelling?

[IsaacHayes]

http://60degreev6.com/showthread.php?t=32908

"2.) The Coolant Temp Sensor on the 3500 is now located in the side of the rear cylinder head as opposed to on the water neck. This called for a 6" extention to the wiring harness."

Might be of better information towards your particular swap.

[gectek]

probjust easier to tap the hole though, and keep the stock location, cant be that bad. plus that would show the temp of the water comming out of the head, better location

[Superdave]

I used 2 LS1 2-wire sensors, one in each head. It helped me diagnose a poor coolant flow problem..


I'd still rather have drilled/tapped the rear head for the larger 3 wire though :P

[skinrock]

So it looks like the only real part I need is the Map sensor connector. I can easily extend the other wires, and drill the gasket holes, but the sensor I need.

Does anyone know the GM part number for this?