Spark plug leads and Holley carburetors!

[JDoidge92]

Hey everyone, just getting my boat ready for this upcoming season and decided to do some bigger ticket upgrades on the 1996 Echelon. Iv purchased a Holley 670 Avenger Marine Carb with all the necessary items to make this install happen (I’ll tell the story below).

After getting the boat fired up with the new carb, I found the spark plugs were jumping a spark from the boot to the block at the plug end. after doing some research on the site I couldn't locate any spark plug lead discussions, which brings me to my question.

-What do you guys recommend for plug leads?! (iv got the 350 small block as a power plant)

 

Now back to the carburetor! So, I pulled the trigger on the Holley 670 Avenger Marine Carb, was told by a buddy it will work well. I was expecting it to be more or less a "plug and play" install, boy was I wrong. Once I received the carb and started removing the old one. I noticed my "angled mounting plate" that comes off the manifold is a spread bore... yet my new carb is a square bore with the ever so slightly different bolt pattern. Then I noticed this carb has a dual fuel intake (primary and secondary) which again I didn't notice upon purchasing. So round 2 in ordering parts I got the 4150 dual fuel rail for the Holley carbs, fuel hose to attached from the existing line to the new 4150 rail (cutting down the metal fuel line to attach) and to accommodate for the different bolt patterns on the "angled mounting plate" I got a 2" Spacer. Once everything was installed it worked PERFECTLY!...... but the dog house is now hitting the flame arrestor as I had to lift the carb 2" to accommodate the hole patterns.

Photos of the install here!

The next question is,

-Do you know where they sell the "angled mounting plate" I speak of, and that’s the correct terminology for that part? I’m hoping to ditch this 2" spacer to gain back my clearance but need something that will accommodate the new carb bolt pattern.

Thanks for your time, and hopefully this experience and headache can help someone out if they too are going for a Holley carb.

 

https://ibb.co/album/YFJQb7   <- If the link above didn't work

[Woodski]

@JDoidge92 - You should be able to find a wedge plate through a Mercruiser parts distributor, although I will add good luck.  Places like Bakes, Michigan Motorz, iboats, wholesale marine may have one on their shelves and good luck with fingers crossed.  It might be hard part to find.  If you don't find one, simply buy a square bore intake manifold as those are plentiful and either source an original GM one or a similar substitute is the Edelbrock Performer RPM.

Why did you swap carburetors?  Given you have a spread bore, it sounds like you have taken off the Weber OEM carb and intend on using a Holley.  The Weber is actually a very good carb and it is quite fool proof which includes the design that minimizes the chance of fuel leaking out of the bowls.  As for plug wires, any good set of universal wires will be fine, if you intend on adding Perfect Pass make sure they are resistor core.

[JDoidge92]

3 hours ago, Woodski said:

@JDoidge92 - You should be able to find a wedge plate through a Mercruiser parts distributor, although I will add good luck.  Places like Bakes, Michigan Motorz, iboats, wholesale marine may have one on their shelves and good luck with fingers crossed.  It might be hard part to find.  If you don't find one, simply buy a square bore intake manifold as those are plentiful and either source an original GM one or a similar substitute is the Edelbrock Performer RPM.

Why did you swap carburetors?  Given you have a spread bore, it sounds like you have taken off the Weber OEM carb and intend on using a Holley.  The Weber is actually a very good carb and it is quite fool proof which includes the design that minimizes the chance of fuel leaking out of the bowls.  As for plug wires, any good set of universal wires will be fine, if you intend on adding Perfect Pass make sure they are resistor core.

Hey Woodski, Thanks for outlining that about the Wedge plate. I wish I looked into that a few days ago before I ordered that 2" spacer, I probably would have had the issue fixed already. 

Do you happen to know what degree the wedge plates are inner boats? I won't be at the boat for a week so I can't get those measurements or angles and would like to order one soon! I did a quick search and think I have found some "universal wedge plates" that could work. these they come in 5 and 8 Degree. Wedge Plate Looks like I will just need to tap 2 new holes in the front of the manifold to bolt this plate up (these holes are already provided if you look at my album linked above)

 

As for your second question about why I changed the carburetor, I was having nothing but issues with this one, it was just giving me a headache and it was the last thing to fix/ replace on the motor. This could have got a rebuild kit completed (which i'm planning on doing) but with the new carb I have electric choke and a few other features which im happy with, and don't have to worry about well out on the water. 

and lastly, that makes things easy, I will order some plug leads up for the 350 motor platform.

Thanks for the help!

[Woodski]

Wedge plate is 15 degrees IIRC.  You can look it up by reading up on shaft angle, the idea is to level the carb relative to water line.