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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Not a 100% on what you are wanting, the harness or plug wire routing and which side?
The factory service manual has component location views in them that help with factory routing of wiring ect.
I know things changed a bit from year to year.
Thing to do might be to visit yer local buzzard nest and take a look at one of their greedily hoarded 96-2000 trucks. It's not impossible that whatever they did on those, would work for your setup. Might give you some ideas anyway. Might even still be able to buy those parts at the GM stealership, if they'll work.
[QUOTE=TTOP350;6441009
The factory service manual has component location views in them that help with factory routing of wiring ect.[/QUOTE]
Indeed, the manual does show the routing. Didn't think to look. Dementia setting in apparently!
Originally Posted by sofakingdom
Thing to do might be to visit yer local buzzard nest and take a look at one of their greedily hoarded 96-2000 trucks. It's not impossible that whatever they did on those, would work for your setup. Might give you some ideas anyway. Might even still be able to buy those parts at the GM stealership, if they'll work.
I'll investigated the truck idea. Could prove fruitful.
True, you might not be able to just "bolt em on", but putting an eyeball on em might just trick acoupla brain cells somewhere into firing simultaneously.
Truck idea will not work with stock F-car exhaust manifolds. The manifolds literally cover the bolt holes for the truck looms.
Hooker headers here. Just looking for as many options as possible. From the manuel:
The 350 HO engine has production Vortec cast iron cylinder heads. These cylinder heads were first used on 1996 trucks with fuel injection, RPO L31. Blah, blah. These cylinder heads have the 1996-1998 Vortec style 8 bolt intake manifold mounting pattern.
Pictured below is a threaded hole (one of two per side) which might/might not be significant.
JamesC
Last edited by JamesC; 09-14-2021 at 08:55 AM.
Reason: Additional info
Thing to do might be to visit yer local buzzard nest and take a look at one of their greedily hoarded 96-2000 trucks. It's not impossible that whatever they did on those, would work for your setup. Might give you some ideas anyway. Might even still be able to buy those parts at the GM stealership, if they'll work.
Sofa has a great idea here. I know because I have done almost exactly what he has suggested.
I have a 95 GMC 305 TBI truck and the factory plug wire brackets to hold the wires at the back of the heads are some of the most functional that I have seen.
I have the part numbers and unfortunately (for me) my engine is still on the test stand. But that means that I can get a few pictures for you.
Give me a few days because I will have to move a bunch of crap in my garage to get to the engine.
Another consideration would be the 1994-97 LT1. The "wire harness support channel" bolts to the block instead of the head, and has provisions for routing the sensor and starter wires as well as the mounts for plug wire retainers. The piece won't care if the wires are routed from the front like an LT1, or the rear like a conventional Gen 1 SBC, so it should work out.
Are you wanting to route the plug wires over the headers and along the valve cover?
All options are on the table.
Originally Posted by NoEmissions84TA
Sofa has a great idea here. I know because I have done almost exactly what he has suggested.
I have a 95 GMC 305 TBI truck and the factory plug wire brackets to hold the wires at the back of the heads are some of the most functional that I have seen.
I have the part numbers and unfortunately (for me) my engine is still on the test stand. But that means that I can get a few pictures for you.
Give me a few days because I will have to move a bunch of crap in my garage to get to the engine.
I'd very much appreciate your effort!
Originally Posted by Vader
Another consideration would be the 1994-97 LT1. The "wire harness support channel" bolts to the block instead of the head, and has provisions for routing the sensor and starter wires as well as the mounts for plug wire retainers. The piece won't care if the wires are routed from the front like an LT1, or the rear like a conventional Gen 1 SBC, so it should work out.
Humm, interesting. I'm hitting a salvage yard tomorrow, if time allows. I hope to come up with something functional—and cost effective!
I've run my plug wires up and along the valve cover. Using the 1/4-20 hole in the block I've installed Moroso's wire loom kit. (Unfortunately it only comes in a chrome finish which I'm not partial to). To space the loom away from the head (so as to provide clearance from the header flange), I've fashioned a spacer from a 5/16" nut. This serves as a standoff and allows the wide base of the loom to fit reasonably well.
Going on memory here, but factory setup wires all run near firewall, and then down under the manifolds up to the plugs. There were wire holders / heat shields integrated with the exhaust manifolds. If that is what you are asking.
I'll peel back the car cover this evening and take a few additional pictures. Might even give it's first start in nearly two years....
Anything in particular you would like to see?
I'll peel back the car cover this evening and take a few additional pictures. Might even give it's first start in nearly two years....
Anything in particular you would like to see?
One head perhaps where I can see the individual looms more closely. Are the the pieces unmodified (I can't quite visualize how they fit)?
Two years.... Whaaat! Shameful, skinny!
Thanks in advance,
JamesC
Liquid, my car wasn't that clean from the factory!
I used to produce (for Center-Bolt Valve Covers) and sell my own Ignition-Wire Separators, that were made from the Company that made that Moroso Set in Post #12 (before chrome-plating, so I could cut and weld them the way I liked).
I need to find some images somewhere...
The only image on hand, has the Wires obscured.
One head perhaps where I can see the individual looms more closely. Are the the pieces unmodified?
Yes. Unmodified. Moving forward, I will trim the base to fit the contour of the header flange and black out the chrome.
I think the photos should illustrate how the looms handle the vertical path from the plugs upward and also the horizontal path parallel to the valve cover.
Arranged in two planes.
The rear most support has a 4 wire loom.
Here you can see the nut spacer behind the Allen head bolt. That's my crude (but effective) stand off.
Individual separators as well.
Excuse the dust. As I mentioned. it's been two years. It did start almost immediately and was up to idle speed in less than a minute despite having no choke and being a somewhat cool 55F. All solid seven cylinders...
Humm, interesting. I'm hitting a salvage yard tomorrow, if time allows. I hope to come up with something functional—and cost effective!
JamesC
Here are the pics of the 95 - ?? truck brackets. Take notice of the 2 brackets that bolt to the back of each head - p/n 14102129 & 14102130.
The 4 wire retainer is 88891792 and the 2 wire is 12132229.
The Moroso clips you see - I had planned to make a "L" tab out of stainless steel and use that 1/4"-20 bolt hole in the heads that you referenced.
I have not had this engine in the car yet, so I can't say for sure if there will be any interference issues.
Here are the pics of the 95 - ?? truck brackets. Take notice of the 2 brackets that bolt to the back of each head
Before hitting the boneyard this a.m., I took a long look at my engine and the way it's shoehorned into the bay. While I love the way the above loom holds the wire at the back of the heads, there was little work room in my car and installation would have been pretty much blind. Of course, one of the first vehicles I searched was a Suburban with the pieces in question. I got a headache thinking about removal and installation. So long story short, I left it. At this point I'm leaning toward the Moroso kit. We'll see.
I have not had that Engine in my Third-Gen for about 14-Years...
It sits on an Engine Stand, as a polished-up display Engine in my Shop.
There is a nice little all Aluminum 6.8L Twin-Turbocharged L92 (Gen-4) Small-Block that drinks E90 (Ethanol) via Holley EFI...
with a Refrigerant (Air-Conditioning) to Water Inter-Cooler in a Holley Hi-Ram, and NItrous-Oxide Injection as an Anti-Lag System.
Also it is the same color Blue!
But, NO LOL it is NOT a Ford color Blue.
It is VHT Brake-Caliper Blue.
LOL, The only cursed (Ford) item that I own...
Would be the Differential in my Funny-Car.
It's not made by Ford... But it is a Jumbo size copy of a Ford 9" Differential.
Made by Mark Williams (11" Ring-Gear), here is the Pinion:
Ford 9" on the Left, and my Pinion on the Right.
I'm the guy that everybody's Wife says not to worry about.
Are you referring to the Moroso set? If you are, the 4 wire loom bolts to the head between 5 and 7. There's an additional stand alone 4 wire keeper that I use for management after the cylinder head. But that's me.
Routing is above the manifold/header just to clarify.
No. The above diagram is from an LG4 but I think that loom may have been transferred to my HO. I can't get a good look at it from above but from the feel it seems secured to something.
IIRC it's mounted on a "bracket" made of a piece of about 3/16" wire bolted to the head. The ones in that diagram that appear to be on either side of the exh man exit, although they are a couple of inches closer to the block than that, are at the 2 ends of that similar piece of wire, which bolts to one of those little ¼" bolt holes up near the top of the side of the block. The wire is bent into a little loop sort of feature to facilitate that. The L69 setup as far as I know uses the same parts.
On the pass side the stock routing was over the top. If memory serves, there was a bracket made onto the heat stove on the exh man about in the middle, pointed vertically and aligned straight front-to-rear, that held a loom for all 4 wires. On the L69 the factory wire boots were 90° for #6 & #8, and straight for #2 & #4. I think they were the same for LG4 but I'm not sure. There was another loom for them on the side of that heat stove mounted horizontally and also along the crank axis for all 4. Both of those were little flat sheet metal tabs about an inch wide or maybe a little wider. The looms had a little latch that clipped into a hole in the metal tabs to hold them on.
The stock routing might work OK with headers but of course there's LOTS of variation in that, so trying to duplicate it somehow, is no guarantee of success, especially on the pass side. The driver's side however, should be compatible with any headers.
Last edited by sofakingdom; 09-19-2021 at 09:24 AM.
I got serious this p.m. I stuck a shop light under the car facing upward, dug up my mini maglite, cleaned my glasses (LOL) and went fishing. This time I could see more clearly and with a long extension and a deep socket to make the extension a bit longer, luck smiled on me. First, my guess at a 7/16 bolt head was correct; second, though I couldn't see the entire bolt head, the socket fell in place; third, I dropped the bolt but managed to not only see it but grab it with a magnet. My experience with cars hasn't always been so, ahem, gratifying. Anyway, the culprit is below.
JamesC
Last edited by JamesC; 09-19-2021 at 03:54 PM.
Reason: Correction
Seems to me at one time I had a myriad of those widgets squirreled away from various cars that passed though. I may even still have them although the great purge of 2014 saw a lot of that inventory off to recycling.
I've run my plug wires up and along the valve cover. Using the 1/4-20 hole in the block I've installed Moroso's wire loom kit. (Unfortunately it only comes in a chrome finish which I'm not partial to). To space the loom away from the head (so as to provide clearance from the header flange), I've fashioned a spacer from a 5/16" nut. This serves as a standoff and allows the wide base of the loom to fit reasonably well. https://www.summitracing.com/parts/mor-72174
Skinny, I ordered the above, but even standing on my head, I couldn't imagine a way the loom would fit. I wonder if you were perhaps off a digit. The following (72-143) looks exactly like the ones you pictured:
Skinny, I ordered the above, but even standing on my head, I couldn't imagine a way the loom would fit. I wonder if you were perhaps off a digit. The following (72-143) looks exactly like the ones you pictured:
My apologies James. The part number in question is the one you have posted. In my eagerness to contribute and the given functionality of my phone, I rushed to give an incorrect solution.
My installation description is still valid though. A spacer is required between the loom and cylinder head. Depending on your approach and specific headers, you may or may not find that the loom requires trimming at the engine attachment point. My needed trimming although in my pictures, you can see that I've skipped that step and allowed the fastener to "deform" the loom slightly.
Hope that's helpful.
Thanks for confirming. I ordered from Amazon so returning/replacing isn't an issue. I'm glad for your help as the Morosos, I think, will absolutely foot the bill.
Well, the finished Moroso (72143)/Taylor (73251) combo is below. The install was more problematic than might be expected. Headers, a brace, a switch, a dipstick tube and a scarcity of work room all contributed to the pain. The pain was somewhat lessened, however, when, by verifying wire resistance, I found that the final wire's core was broken at the terminal. A quick fix and all was good. In the end the routing is far superior to the under-header routing that I'd used previously. Thanks, All.
Nice to see that worked for you James.
I've never be a fan of running the wires under the headers as I've always liked the visual of well managed wiring (it's my trade too).
Curious as to what you had to do for fitment. I've seen that the header flange can get in the way and in some cases may have to be relieved with a die grinder for access to the holes in the head. Did you have to fashion a spacer as I did?
09-13-2021, 08:25 AM
Go buy a lottery ticket. 
