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'89 R3500 Crew Cab 2wd to 4wd conversion & beyond

Started out with 2wd TBI350 with SM465 to current 4wd with 454, 700r4, NP241
Overview Gallery Discussion
That's rectangular port.

I went back to double check the Ramjet and that one sold! That one is a "square oval" thats the size of a oval port but with more squared corners, it matches the GMPP and Edelbrock RPM Oval port heads.
 
folkenheath said:
That's rectangular port.

I went back to double check the Ramjet and that one sold! That one is a "square oval" thats the size of a oval port but with more squared corners, it matches the GMPP and Edelbrock RPM Oval port heads.
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I guess that answers my question on if they sell.

I do have an fittings on the engine for the heater hoses. That was something I did on the previous 454.
 
I like using the newer PCV hoses with the fomed plastic tube. I figured out one that had the bends I need, GM Genuine Parts 93441238. I did have to cut an inch off the tube. The made in Mexico tag on it is a bit ridiculous.

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From what I read you have to piggy back the factory ECU with the TermX to keep the emissions equipment. I made some aluminum covers for the EGR and Evap ports.

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I changed out the bypass hose fittings. The new ones are brass and it occurred to me there could be a corrosion issue with brass and aluminum in contact. Then I realized the coolant temp sensor is brass.

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Noticed this spot on the upper plenum. Not concerned about it, but I was trying to decide if it was something broken off or just bad casting.

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You should use a crankcase breather somewhere if it doesn't have one with your intake/valve cover combo. At WOT or high load (low vacuum) I wouldn't trust a PCV only with a sealed oil fill.

One of the oil fill caps should be a breather as well...
 
I have been thinking about the breather. The PCV is the M/E Wagner dual flow unit that works really well on the C10 and the old 454. I also have the factory breather tube on the other side that is an elbow from the valve cover to the intake. Where the elbow connects to the intake looks like a port that wraps around the top of the throttle body opening and dumps in on the opposite side. I wondered if it was enough.

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So that is connected to the atmospheric (out)side of the throttle?

It might be enough then, I couldn't see that one on the recent pictures, only your fancy adj PCV.

If that's all the factory L29 or L21 does then its likely fine, you are just burning all the oil fumes.

The only way to know for sure is have a MAP sensor connected to the crank case. Or a non locking sealed oil dipstick, or if you start getting oil leaks easily you might want to address it.
 
folkenheath said:
So that is connected to the atmospheric (out)side of the throttle?

It might be enough then, I couldn't see that one on the recent pictures, only your fancy adj PCV.

If that's all the factory L29 or L21 does then its likely fine, you are just burning all the oil fumes.

The only way to know for sure is have a MAP sensor connected to the crank case. Or a non locking sealed oil dipstick, or if you start getting oil leaks easily you might want to address it.
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I had that happen on my 12 litre CAT, I had to add breathers to relieve the pressure and that stopped the leaks
 
In the intake vacuum? So its just another PCV valve? Why would they make it go all the way up to the TB just to enter behind it anyway?

In that case I would block it off in the intake and make it a breather in the valve cover, you don't need two PCV valves to manifold vacuum.

You could also block it off completely and make the other oil fill a breather.
 
Coil mounting is done. The driver side is straight forward.

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The passenger took some adjusting. I had accounted for the intake tube, but I didn't account for the throttle bracket. I had to move #5 coil further back so the harness plug could clear the throttle bracket.

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I used 1" long thru bolts into threaded aluminum spacers and then nuts with free-spinning washers.

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It would have been a lot simpler if they'd made the mounting tabs flush with the back of the coil.
 
@mrk5 when the 8.1 come out they had them in the gmt455 rucks / 3500-hd and the had a duct across the front to the throttle body . but yes in the early days i might of been for the air box line up .
 
Intake manifold designs like that are also an attempt to even the airflow distribution, if the air enters in the center and then hits a wall and/or splits and goes outward it can help supply more even airflow. The Ford 302 intake from the late 80s/early 90s was similar.
 
The 400 truck air filter assembly was directly in line with the L29 and L31 Vortec small block. My money is on they did the side intake for convenience, not performance.
 
Well, it certainly isn't a high RPM performance intake I agree, its got long low cross section runners for low end torque. Also, even airflow doesn't necessarily mean performance. However, they could of just went straight in top and the over to the side like the TBI, or most aftermarket singe plane MPFI intakes, so it's at a minimum a combination of both reasons.
 
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