Plug Wires Over or Under?

What are the relative merits of running plug wires under the headers (as in stock) or over the valve covers? (350)

Looks like their life would be cooler in the "over" config.

Thanks, y'all!

I would think over the valve covers would be better for the plug wires, but headers don't give you many options.

Get some plug wire holder brackets that attach to the valve cover bolts. they sure help to keep them off the engine and hot points. we have them on Ian. when I replaced the wirers I got some electrical wire rubber o rings to put around the wires where they touched the bracket for insulation. Got all the parts at NAPA

Everyone will have an opinion on this but remember Heat rises. It really does not take that much longer to run the wires correctly underneath as in factory installation. What everyone hates is running the wires through the motor mounts. Which is the correct way and the spark plug wires will not be as affected by the heat off the headers.

Jetpilot

Actually, I didn't forget ... and I also didn't mention I'm running a highrise hood that evacuates the worst of the engine house heat. Figured that would be a wash ...

I'm running headers.I originally tried to run my wires as they were stock, under the exhaust manifold, but running them this way the wires were very long. I replaced my wires a couple months ago and went with the wire standoffs which worked great. They are away from the headers, wires aren't as long and when you pop the hood, they look really good and organized. I think I spent less than 20 bucks on the standoffs.

jedlevine , I run mine over the top of the engine. Ecklers sell a good product called Koolsox. They are boots that slide over your wires to protect them from header heat. They work great....no more replaceing expensive wires with this product. You can find them in Ecklers cat. on page 124 of there newest cat. cost : $44.99. Order # 44230. They say for 97-04 vettes..but they work on any engine. Hope that helps.

I'd go with the stock routing, and keep the chrome wire and distributor shields for looks. Otherwise it looks like a camaro engine. The slightly longer wires won't noticeably hurt performance. Joe

Engine house already looks like a Summit or Jeg's catalog page. Dist is MSD ProBillet, shields are long gone (before I got the car).

I'll check on those heat boots, either way.

One of the upsides (to me) of a 75'er (NOM) was building up that engine from 165 choked ponies. Heads, headers, Magnaflows, MSD, cam, rollers, cam, manifold, Q-Jet clone, water pump, flexfan, etc. (And with tall valve covers and a triangle air filter, it doesn't look like a Camaro mill.)

Oh yeah, the other upside is fiberglass floors!