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6.0 and NV4500 w/ external slave - which exhaust manifolds or headers?

jtrux

jtrux

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I searched and posted in my build thread but posting separately tends to get more responses so here it goes.

I'm installing a Gen 3 LS in my '91 Suburban with an early NV4500. I'm going to be using the Quick Draw bell housing that utilizes an external slave. Question is, what is the best headers or manifolds to clear the slave? I've read some reviews on Sunmit where guys had clearance issues running swap manifolds with a factory hydraulic SM465 and since that incorporates an external slave like my set up, I am assuming I might have issues as well. So anyone running an external slave with an LS swap, what are your running for headers or manifolds? I want a 2.5" outlet also so that rules out some of the cheaper manifold options.
 
Not many running your exact combo here that I can recall. I know you already got the bell housing but this is where the stock Gm bell shines with the internal slave. Zero issues with exhaust. I know that don’t help you answer your question and I completely understand the limited ability to find the stock Gm bell sucks.

Unless someone that has an external slave pops up you might have to go through a process of mocking different options up. Which sucks ordering and possibly sending stuff back when it don’t fit. Which, by itself might make it worth your while to look for a ‘96 and up Gm bell to switch to instead.
 
Wow- I don’t think I’m going to be much help, but I saw the title of the thread and my jealousy level is high. That combo would have been a dream for me, but not in Californistan! The smog boss would never allow it!
 
ZooMad75 said:
Not many running your exact combo here that I can recall. I know you already got the bell housing but this is where the stock Gm bell shines with the internal slave. Zero issues with exhaust. I know that don’t help you answer your question and I completely understand the limited ability to find the stock Gm bell sucks.

Unless someone that has an external slave pops up you might have to go through a process of mocking different options up. Which sucks ordering and possibly sending stuff back when it don’t fit. Which, by itself might make it worth your while to look for a ‘96 and up Gm bell to switch to instead.
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The early NV that I have really limits my choices. Some people have heavily modified their early NV case to accept internal slave but unfortunately that's out of my capabilities so I'm left running external. The early NVs ran an external slave on the passenger side below the starter.
 
scouthead said:
Wow- I don’t think I’m going to be much help, but I saw the title of the thread and my jealousy level is high. That combo would have been a dream for me, but not in Californistan! The smog boss would never allow it!
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I figured you would be able to put a new engine in an old rig but not the other way around?
 
If i were you I would just buy Summit white box cast manifolds and be done. I as well was looking at the Quick Draw brand bellhousing and saw that it tucks the slave much tighter in then the factory Sm465 style or retrofit Advanced Adapters bellhousing.

For reference:

Quickdraw housing pic

Screenshot_20240710_140836_Chrome.jpg

Hooker LS swap manifolds on my 91' Suburban with 4l80e. Don't waste your money on these, they are the exact same as the white box manifolds but double the price with crap ceramic coating on them.

20190719_204026.jpg

Underside shot of a simple bent down pipe i ran as the factory did.

20190728_134213.jpg

You can see that you will have plenty of room to the bellhousing. And these manifolds use factory manifold gaskets for from any truck and flange gaskets from an ls3 camaro if I remember correctly.

You also don't have to deal with sealing issues of headers, possible burnt plug wires, additional cost, etc all for a marginal HP gain at high rpm where you won't likely be anyway with a dump truck shifting nv4500...

Manifolds I would suggest:


Edit: Those are a 2.5" sized collector. The quickdraw pic is a Tr4050 but the NV4500 housing is the exact same way.
 
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I run 03 yukon 4x4 5.3 manifolds on my c10 build and they clear just fine . And i had to notch a tiny bit of frame lip on pass side only . But my motor is 1.25" setback from stock . Driver side set in 45* and tilt up to head and bolt in just fine .
 
jtrux said:
I figured you would be able to put a new engine in an old rig but not the other way around?
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Yeah, well technically… sorta. Yes on the newer engine, and cannot have an engine that came out of a vehicle that had a higher GVWR than the vehicle it’s going in to.

Also, they will inspect and run the numbers on the engine block. An engine that was originally sold mated to an auto trans can never be attached to a manual trans… a manual trans motor CAN be used with an auto trans?

And ALL of the emissions components from the newer donor vehicle need to be utilized and functioning as they were from the factory in the donor vehicle… so if your particular referee wants to be a douche and nitpick over things like:
-what catalytic converters you have
-if you used an aftermarket fuel pump
-aftermarket exhaust manifolds or headers
-factory wiring and computers

They know full well that some of the factory components may be impossible to retrofit, and they know they have full power and control over signing Off on your particular project, or making your life an impossible expensive hell with a vehicle you will never be able to drive on the road again. I’ve heard horror stories. I’ve also heard people say it’s worth driving outside of your area to deal with particular offices and referees that are known to be reasonable. As far as I’m concerned it’s just not realistic to undertake as an individual swimming against the tide here.
 
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scouthead said:
Yeah, well technically… sorta. Yes on the newer engine, and cannot have an engine that came out of a vehicle that had a higher GVWR than the vehicle it’s going in to.

Also, they will inspect and run the numbers on the engine block. An engine that was originally sold mated to an auto trans can never be attached to a manual trans… a manual trans motor CAN be used with an auto trans?

And ALL of the emissions components from the newer donor vehicle need to be utilized and functioning as they were from the factory in the donor vehicle… so if your particular referee wants to be a douche and nitpick over things like:
-what catalytic converters you have
-if you used an aftermarket fuel pump
-aftermarket exhaust manifolds or headers
-factory wiring and computers

They know full well that some of the factory components may be impossible to retrofit, and they know they have full power and control over signing Off on your particular project, or making your life an impossible expensive hell with a vehicle you will never be able to drive on the road again. I’ve heard horror stories. I’ve also heard people say it’s worth driving outside of your area to deal with particular offices and referees that are know to be reasonable. As far as I’m concerned it’s just not realistic to undertake as an individual swimming against the tide here.
Click to expand...
That's why I invested in no smog vehicles and upgraded all of them to newer running gear with no hassle.
Yeah it cost a little money for the vehicles but way cheaper in the long run
 
jtrux said:
Just so I'm clear did you use the ball and socket or flat gasket ones?
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I used the flat gaskets ones. They worked fine but then in my opinion you have to put flex in the exhaust system somewhere. You can kinda see in my picture I added flex couplers to both sides of the system for the engine moving under torque.

The ball and socket ones I believe allow a little more movement... Completely up to you this is just the thought process I went through in that specific build.
 
CriticalAction said:
I used the flat gaskets ones. They worked fine but then in my opinion you have to put flex in the exhaust system somewhere. You can kinda see in my picture I added flex couplers to both sides of the system for the engine moving under torque.

The ball and socket ones I believe allow a little more movement... Completely up to you this is just the thought process I went through in that specific build.
Click to expand...
I've read where some people hate the ball and socket design. I've never really had a problem with them that I can think of but you bring up a valid point. I'll decide tonight what I want to do.
 
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