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Valve cover question

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Old Jan 30, 2011 | 01:42 PM
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Valve cover question

I was wondering if stock 350 valve covers will accommodate rocker arms with a 1.6 ratio?
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Old Jan 30, 2011 | 01:50 PM
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Chevy86 IROC-Z's Avatar
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Re: Valve cover question

yes but only if the Rocker arms are of the narrow type.

these would work.


too bulky and wont fit the center bolt style covers.

Another thing to consider is the bolt. Sometimes the bolt sticks out too high and will not allow the cover to sit flush with the head. So you may need tall valve covers. Just call the manufatures tech and ask if the particular rocker arm will fit inside the cover.
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Old Jan 30, 2011 | 02:18 PM
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Re: Valve cover question

The center bolt valve covers offer different clearance issues. Aftermarket center bolt covers are not as bad. An option is to use a valve cover extension.

I was running some fabricated valve covers on my engine. I have long valves for a higher spring install height. Add on stud girdles so that the rocker studs don't flex under the high spring pressures and clearance under the valve covers gets tight. My old covers just fit but my newer, nicer fabricated covers wouldn't fit.

Doing a quick Ebay search, I found some nice valve cover extensions. This raised my new valve covers up enough so that there's no more interference. The extensions are more designed for people like you who want to retain a factory cover look but need the added room of a tall cover.
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Old Jan 31, 2011 | 06:58 AM
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From: Silver Creek, Georgia
Car: 1986 Iroc Z
Engine: 5.0 TPI
Transmission: 700R4
Axle/Gears: 3.42
Re: Valve cover question

I appreciate the feed back, I was wondering about the width. Sorry I should have specified. I have the perimeter bolt pattern. The reason I ask is because I did an engine swap, a 305 to a 350, and used my old 305 valve cover, assuming they would suffice, well they didn't. When I put them on they were a tight fit, but I didn't realize the rockerarms were going to rub the side of the valve cover. After a 2 weeks the valve covers cracked. So I am wondering if I going to have the same clearence issues with aftermarket 350 valve covers.
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Old Jan 31, 2011 | 11:05 AM
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Re: Valve cover question

They should fit, except that the Poly-Locks might be too tall.

There is no difference between 305 and 350 valve covers, as such. There are year model differences, but within a given year, they are the same.

That's stock ones. Aftermarket, they could be ANYTHING. All bets are off. Some fit well, some are junk. Usually the shinier the chrome and the less they cost, the more likely it is that ABSOLUTELY NOTHING WHATSOEVER during the design or mfg process was done by anyone who has ever even SEEN an American car.

Usual cause of rockers rubbing the VCs is putting the VCs on backwards.They have a DEFINITE intake side and exhaust side. The int side stands up straighter; the exh side is sloped in more. If they're backwards, the push rod end of the rocker may hit the VC. Since that side of the rocker is slightly shorter with 1.6 rockers, the problem tends to be less severe with those. However, putting the VCs on right will almost certainly prevent problems.
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Old Jan 31, 2011 | 11:13 AM
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Engine: 350 Tuned Port Injection, for now.
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Axle/Gears: Posi - 3.23
Re: Valve cover question

The 2nd picture of the bulky rocker, I have. I shaved down the flange on the oem valve cover bolt tubes. The vc then slid in perfect but the baffle that houses the PVC valve is too wide. But the othside of the vc dropped in easily but wouldn't sit all the way down. So this leads me to believe that the poly lock is too tall. I'm gonna sell my bulky RR and buy a thinner body style. Hope fully the polylocks on the set that I'm gonna buy are not too tall.
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