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Just put a set of GT40P heads on my 1990 5.0, and I'm noticing a bit of lifter tick/valvetrain noise.

It's a completely stock motor aside from the heads, stock cam and I put in brand new lifters and push rods when I did the swap and I'm using the stock GT40P rocker arms/valves/valve springs.

I've heard of some guys having to use longer push rods and/or rocker arm shims in order to get these heads to work properly, but I've also heard of it working just fine with a stock cam and stock motor. Since my piston-valve clearance was good I figured I would be fine, but something seems to be off.

The car runs/idles/drives fine with plenty of power, so it doesn't seem like there is anything critical going wrong, but something must be off a tad because new lifters should not be this ticky.

Can anyone give me some input on pros and cons of using these heads on a stock 5.0???

Cheers!
 

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Just put a set of GT40P heads on my 1990 5.0, and I'm noticing a bit of lifter tick/valvetrain noise.

It's a completely stock motor aside from the heads, stock cam and I put in brand new lifters and push rods when I did the swap and I'm using the stock GT40P rocker arms/valves/valve springs.

I've heard of some guys having to use longer push rods and/or rocker arm shims in order to get these heads to work properly, but I've also heard of it working just fine with a stock cam and stock motor. Since my piston-valve clearance was good I figured I would be fine, but something seems to be off.

The car runs/idles/drives fine with plenty of power, so it doesn't seem like there is anything critical going wrong, but something must be off a tad because new lifters should not be this ticky.



Can anyone give me some input on pros and cons of using these heads on a stock 5.0???

Cheers!


I had a similar problem and found that the Valve springs on the P heads are questionable even with a stock mustang cam. I would change the valve springs as that is what saved me from coil bind. But my cam is pretty aggressive .525 lift at 1.6.
 

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the stock valve springs are junk..did you measure for pushrod length?
 

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Change the springs, check rod length, and running roller rockers is going to be noisier.
 

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The stock springs are weak and cannot fully support the mustang cam. You will probably have to invest in some valve springs like the other suggested.
 

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The stock springs on gt40 heads are lucky to support the weight of the valve covers :kooky:
 
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