‘68 L68 427 tune up tips
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Joined: Mar 2022
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‘68 L68 427 tune up tips
Still going thru my to-do list on my recently purchased ‘68 427 L68 Tri-power car. It’s the 400hp version with the hydraulic cam and 10.25:1 compression. I’ve just about got the brakes squared away and with a tuneup I’ll feel comfortable with taking it out for a drive. The engine sounds good as there are no sounds of concern but not as smooth as it should be. I’m thinking the years of storage, idling and bad gas has crapped up the plugs somewhat.
What plugs are you guys/gals running? AC Delco? And what heat range?
Considering the MSD cap and rotor because they have brass contacts instead of silver.
Points and condenser ?
Many years back I built an engine for my Charger and it ran great. The car then went into the body shop for about 2-3 months and it did a lot of idling.
when it got out of the shop it looked great but ran bad. Wasn’t happy but a new set of plugs set it right. It’s kind of the same thing now with the vette.
I have more to do but it’d be good motivation to be able to rake it for a little drive in the mean time.
What plugs are you guys/gals running? AC Delco? And what heat range?
Considering the MSD cap and rotor because they have brass contacts instead of silver.
Points and condenser ?
Many years back I built an engine for my Charger and it ran great. The car then went into the body shop for about 2-3 months and it did a lot of idling.
when it got out of the shop it looked great but ran bad. Wasn’t happy but a new set of plugs set it right. It’s kind of the same thing now with the vette.
I have more to do but it’d be good motivation to be able to rake it for a little drive in the mean time.
Racer
Joined: Apr 2010
Posts: 271
Likes: 158
Congratulations Mike on the L68. Nothing quite like a Tri-Power. In my ‘69 L71 I’ve had good success running Delco R45XLS plugs.
I would buy the Chevrolet service manual for your car. They are available on eBay and the NCRS bookstore. It will layout a process for a tune up....set the timing, set the idle, set the carb float levels, etc.
if that does make it run smoother you at least have a baseline to start any trouble shooting activities.
I would buy the Chevrolet service manual for your car. They are available on eBay and the NCRS bookstore. It will layout a process for a tune up....set the timing, set the idle, set the carb float levels, etc.
if that does make it run smoother you at least have a baseline to start any trouble shooting activities.
Le Mans Master
Joined: Mar 2004
Posts: 7,493
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From: Little Rock AR
If you want a better distributor cap take a look at an Echlin from NAPA. They have the brass contacts and fit like a glove. The Autozone ones will pull out the spark plug wire terminals when you remove a wire -HA!
I like the Autolite plugs better. They have a wider heat range. Seem to foul less.
I like the Autolite plugs better. They have a wider heat range. Seem to foul less.
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If you want a better distributor cap take a look at an Echlin from NAPA. They have the brass contacts and fit like a glove. The Autozone ones will pull out the spark plug wire terminals when you remove a wire -HA!
I like the Autolite plugs better. They have a wider heat range. Seem to foul less.
I like the Autolite plugs better. They have a wider heat range. Seem to foul less.
NAPA has been sketchy for old car parts lately and their computer system somewhat unreliable.Ive fell back on autolite plugs when I have dealt with engines prone to fouling because they tend to run hotter.
Every engine seems to have its plug brand it likes. My Mopars 340 likes Champion, our Jeep 4.7 NGK, and my buddy who had a Chevelle with a 454 swears nothing but ACDelco would Be the only plug that’d work.
I’m inclined to look for a slightly hotter plug as I don’t expect to be pushing it that hard.
Thread Starter
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Joined: Mar 2022
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Congratulations Mike on the L68. Nothing quite like a Tri-Power. In my ‘69 L71 I’ve had good success running Delco R45XLS plugs.
I would buy the Chevrolet service manual for your car. They are available on eBay and the NCRS bookstore. It will layout a process for a tune up....set the timing, set the idle, set the carb float levels, etc.
if that does make it run smoother you at least have a baseline to start any trouble shooting activities.
I would buy the Chevrolet service manual for your car. They are available on eBay and the NCRS bookstore. It will layout a process for a tune up....set the timing, set the idle, set the carb float levels, etc.
if that does make it run smoother you at least have a baseline to start any trouble shooting activities.
The 45 plug would seem hot for your L71. Ive been digging thru what I have and found my owners manual lists the AC-43N for my engine which is a cold plug. I was considering a 44 because though I’d occasionally put my foot in it I’d likely be taking it easy so a hotter plug would be better.
I pulled some plugs today and they were pretty much as expected...
A clean set should help.
