Understanding marine dbw vs cable misc.

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Singlecab

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I put in a marine intake early last year. It is a superior intake to the stock vortec, there really can be no question on that. It is free of all interior obstructions and absent the spider has an enormous volume which is advantageous for torque building. It has a standard fuel rail system which means you have many options regarding fuel injector selection. Having said that, for a truck motor the end result performance gain is pretty minimal. It's not nothing, but it's minimal. I would expect it to be a more reliable fueling solution (look at all the posts of people who have issues with their spiders vs the hundreds of millions of vehicles with standard fuel rail injectors which run without issue through their service lives) which was my aim when I went through my motor last year. Lastly, if the spider had any advantage over fuel rail injectors why didn't any other manufacturer, including GM, copy it? If you do get an intake try to get it with the accessory bracket (kind of an S shaped steel bracket that spans the manifold) because it makes it much easier to mount the canister purge valve and attached wire loom to keep the install clean. If you convert to cpc ignition at the same time as I did you won't have to worry about the ICM mounting either and what you'll end up with is a cleaner than factory installation.

With regards to your questions:
-Do any of you know the differences in those specific 4 hole throttle body 5.7 vortec marine intakes? No, mine had the same 3 hole tb as stock but on the PPED forum there is some discussion about getting an adapter for it. Given the dates of postings though there may not be adapters available any more.
-Am I wasting my time trying to install the marine intake to begin with as its not going to see high revs most it's life? You don't need it since the stock manifold is sufficient. But as mentioned it is superior to the stock manifold. May be easier to tune too.
-If it's worth swapping over, can you interchange either the top half of the intake? The top halves are not interchangeable. Beyond the big hole where the spider penetrates the upper manifold the stock also has carveouts in the upper manifold for pcv and canister purge valves. So they're not the same shape.
-or do they make a 4 bolt to 3 bolt throttle body adapter that I can't seem to find? As mentioned, take a look at the PPED forum. I know it was discussed.

The EGR tube is really easy to fix. You need two 5/8-3/4 flare adapters, two 3/4 flare nuts, and one 5/8 flare nut. The stock EGR tube is 5/8 and the middle foot or so of it is smooth SST so you cut it in the middle and flare it for a union. The 1999 Silverado uses a "divorced" EGR which can be mounted outboard of the AC compressor (basically where the pulley of a whipple sc would go if you had a whipple sc). Cut the adapters off of the 1999 EGR tube ends which leaves enough SST to flare (the 1999 EGR uses a 3/4 tube). Feminize the 5/8 end of one of the 5/8-3/4 adapters and put it in the manifold and then use the other adapter and flare nuts to put it all together. If you do the EGR this way you can keep the stock coolant hoses. Never could figure out why the author of the original procedure thought you needed a radiator hose from a pre-96 truck anyway.

The marine intake isn't hard to do and you don't have to abandon anything a stock truck has to put it in. You can buy new 24# Denso injectors for about $150 for 8 on ebay which are intended for use in marine engine overhauls (they made a lot of Marine Magnums). My intake came off of a 2005 Mercruiser with a 305 and cost $550 to the door. Probably spent an extra $400 on everything else (new injectors, injector harnesses, wire, 16 pin metripac, vac tubing, thermostat, canister purge valve, water neck, tb spacer, egr fun (not fun - easy solution after a half dozen failed solutions), etc). So it isn't a cheap thing to do. But it does work exceptionally well done right. Is it worth it? I have no regrets but it certainly isn't something you need for a 383. But by that logic a 383 isn't something you need either.
 

Singlecab

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Hello all. I’m extremely new to the forum, so forgive me for reviving an old thread

I am in the process of what initiated as a simple rebuild, but due to all the machine shops in my area being either overwhelmed, or retiring...the project took on its own life. Now 5 months in I have discovered all the mods that seem to offer solutions to issues I’ve dealt with for years of owning this truck(23).

At this point I’m at comp springs, lunati 20080660 cam, comp roller tip 1.52, 0411, marine intake

I only found the intake yesterday, and it’s being shipped. Jeremy you mentioned a list of parts associated with the intake, and as green as I am I have to clarify

1)does #24 injector mean 24lb/hr, and is that sufficient for 400hp in theory
2)will the water neck off the stock intake not work on the marine?

I’m still feeling my way in the dark as far as gathering everything I need, so any suggestions regarding coils, wires, harness to pcm, fuel pump upgrade if needed...would be greatly appreciated.

As this is my absolute first involvement with any online social platform, I’m fine with constructive criticism relative to etiquette. If I’m off with the post just direct me to the right place. Thank you gents
 

Singlecab

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Hello all. I’m extremely new to the forum, so forgive me for reviving an old thread

I am in the process of what initiated as a simple rebuild, but due to all the machine shops in my area being either overwhelmed, or retiring...the project took on its own life. Now 5 months in I have discovered all the mods that seem to offer solutions to issues I’ve dealt with for years of owning this truck(23).

At this point I’m at comp springs, lunati 20080660 cam, comp roller tip 1.52, 0411, marine intake

I only found the intake yesterday, and it’s being shipped. Jeremy you mentioned a list of parts associated with the intake, and as green as I am I have to clarify

1)does #24 injector mean 24lb/hr, and is that sufficient for 400hp in theory
2)will the water neck off the stock intake not work on the marine?

I’m still feeling my way in the dark as far as gathering everything I need, so any suggestions regarding coils, wires, harness to pcm, fuel pump upgrade if needed...would be greatly appreciated.

As this is my absolute first involvement with any online social platform, I’m fine with constructive criticism relative to etiquette. If I’m off with the post just direct me to the right place. Thank you gents
I just realized the marine thermostat is four bolt. The guy I am getting it from has the marine housing, but in the pics it appears massive and specific to marine use. Where do I get a four bolt housing/neck and gasket?
 

JeremyNH

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Two of the bolts holes are the same as the vortec manifold so just use those. The other two I filled with stainless bolts with thread sealer since I was afraid water would accumulate there and possibly crack the manifold during winter. I'm using the stock water neck. I only mentioned the water neck because the PPED forum (prior to it being shutdown) had the original and longest running thread about it and they said to use the water neck and hose for a pre-96 truck. I made the stock neck and hose fit just fine so didn't understand why they chose to go that route.

Stock MI injectors flow 24lbs/hr at 43.5 bar so 27 lbs/hr at the 58psi regulator pressure. General rule of thumb is 80-85% injector duty cycle which is 390-425HP for 27 lb/hr flow. At 400HP you should be fine.
 

L31MaxExpress

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Two of the bolts holes are the same as the vortec manifold so just use those. The other two I filled with stainless bolts with thread sealer since I was afraid water would accumulate there and possibly crack the manifold during winter. I'm using the stock water neck. I only mentioned the water neck because the PPED forum (prior to it being shutdown) had the original and longest running thread about it and they said to use the water neck and hose for a pre-96 truck. I made the stock neck and hose fit just fine so didn't understand why they chose to go that route.

Stock MI injectors flow 24lbs/hr at 43.5 bar so 27 lbs/hr at the 58psi regulator pressure. General rule of thumb is 80-85% injector duty cycle which is 390-425HP for 27 lb/hr flow. At 400HP you should be fine.
I was feeding my 383 to ~450 hp with the stock spider at 70 psi for 24.6 lb/hr.
 

Singlecab

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I bought the updated spider during my initial parts gathering. I was preparing to 383 a four bolt I had put back for a while, but like I said Chattanooga is having a machine shop crisis. The only reason I opted for the marine intake when I discovered it’s existence was due to the fact that it’s cast iron. All the intakes I have are very chewed up around the water ports, and I’ve changed gaskets about 4 times in 23 years, and lived with water consumption of some degree almost all along. Anyway I hope the new intake gets along better with the block being like material is all. If it’s a huge waste of time then I guess I’ll put the intake away and buy a dorman replacement. If it’s not a huge pain to wire injectors then I like the idea of external junk This truck would spin tires in a light rain, and put a weathered smile on my face getting on the highway, and still got 17mpg hwy at 330k miles. It’s a single cab short bed so I think it’ll be almost frustrating with over 300hp. It’s not power that’s driving my mods at all. The 0411 swap is strictly to support coil packs in hopes I can go ten years without having to replace plug wires and cap multiple times. Let me know if I’m waisting my time. I have stripped the loom back from my pcm connectors, and removed all the old pins out of the new connectors, and received the pin out from lextech. Truly I love original, and if I’m smoking crack thinking my problems are going to go away then I will listen. All I wanted originally was a little cam song
 

L31MaxExpress

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I bought the updated spider during my initial parts gathering. I was preparing to 383 a four bolt I had put back for a while, but like I said Chattanooga is having a machine shop crisis. The only reason I opted for the marine intake when I discovered it’s existence was due to the fact that it’s cast iron. All the intakes I have are very chewed up around the water ports, and I’ve changed gaskets about 4 times in 23 years, and lived with water consumption of some degree almost all along. Anyway I hope the new intake gets along better with the block being like material is all. If it’s a huge waste of time then I guess I’ll put the intake away and buy a dorman replacement. If it’s not a huge pain to wire injectors then I like the idea of external junk This truck would spin tires in a light rain, and put a weathered smile on my face getting on the highway, and still got 17mpg hwy at 330k miles. It’s a single cab short bed so I think it’ll be almost frustrating with over 300hp. It’s not power that’s driving my mods at all. The 0411 swap is strictly to support coil packs in hopes I can go ten years without having to replace plug wires and cap multiple times. Let me know if I’m waisting my time. I have stripped the loom back from my pcm connectors, and removed all the old pins out of the new connectors, and received the pin out from lextech. Truly I love original, and if I’m smoking crack thinking my problems are going to go away then I will listen. All I wanted originally was a little cam song

I went back to a distributor on mine. LS coils are a durability problem in the Express/Savanna vans due to the etreme heat. I vacuum vented my distributor the same way the later opti sparks are and use only MSD caps and rotors. I think I have had the same cap going on 6 years now (ran the cap 4 years before the 24x) with no signs of wear. Once I went to good wires like Taylor, I never had an issue with them as long as they stayed off the headers.
 

Singlecab

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That sucks to hear. I figured it would be amazing. My 2011 6.2 is so crisp at 75k miles I figured I’d just buy whatever coils are in it and use them on the 98. I’m definitely lost when it comes to coil selection. I’ve spent about 500 bucks on pcm, tune, connectors, and reluctor. I would hate to turn back now. What coils were you using that gave you fits?
 

L31MaxExpress

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That sucks to hear. I figured it would be amazing. My 2011 6.2 is so crisp at 75k miles I figured I’d just buy whatever coils are in it and use them on the 98. I’m definitely lost when it comes to coil selection. I’ve spent about 500 bucks on pcm, tune, connectors, and reluctor. I would hate to turn back now. What coils were you using that gave you fits?
D585s

I read a tune from a truck that had them stock too. Just to make sure the dwell settings were correct. After 2 or 3 of them failed that came off a lower mileage 5.3L I had picked up with a broken block for the accessory setup I figured maybe they were just old. I replaced all 8 with new Delphi. Within a year I had 2 more fail. When I built the 383 I had already decided to go back to the Vortec distributor running the same DUI module and Coil. It runs so crisp and smooth now like it did when it was new. Hopefully the coils will stay cooler in your truck then they did in my Express with headers. My coil failures were all in the hottest summer months making me believe it was due to extreme heat. I think location also did not help on mine. I had to mount mine to the top of the distributor block off cap on relocation brackets, at the rear of the engine compartment right up against the dog house cover and use vortec plug wires. When the engine was shut-off all the engine/header heat focused itself on that insulated cover and baked the coils.

Anybody still using a distributor should vacuum vent the base like the later optisparks. It elimimates ozone and moisture buildup and related corrosion allowing for exponentially better life of the cap and rotor.
 
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Singlecab

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Yeah I wasn’t ever disappointed really by any performance when stuff was fresh. I bought a summit aluminum distributor, and could easily find a spot for it on some vacuum. I don’t know how the opti spark was rigged, but any vacuum would keep it dry I guess. Man I guess I have some serious reconsidering to do. I doubt I could return much of it, but that’s not a good excuse to hack up my truck.
 
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