# Cam Change Out?



## Sdpepper (Jun 3, 2021)

I purchased a 67 Goat recently and in the process of making it my own. Toward that end, I eliminated the Flowmasters as they were simply too loud for my taste. Went with Dynomax Turbos but beginning to think the 400 ci engine was equipped with a beefier cam. Another guy thought the same thing hearing it run. How difficult would it be to install a milder or stock cam and what might I expect a knowledgeable mechanic to charge? Would I need to replace the springs, push rods, etc? The car has aftermarket aluminum Edelbrock heads and headers. Am I correct that going with a milder/ stock would quiet the engine?


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## PontiacJim (Dec 29, 2012)

Sdpepper said:


> I purchased a 67 Goat recently and in the process of making it my own. Toward that end, I eliminated the Flowmasters as they were simply too loud for my taste. Went with Dynomax Turbos but beginning to think the 400 ci engine was equipped with a beefier cam. Another guy thought the same thing hearing it run. How difficult would it be to install a milder or stock cam and what might I expect a knowledgeable mechanic to charge? Would I need to replace the springs, push rods, etc? The car has aftermarket aluminum Edelbrock heads and headers. Am I correct that going with a milder/ stock would quiet the engine?


Going to a smaller cam could actually get you in trouble if you don't spec it correctly. Do you know if you have a roller cam or flat tappet hydraulic?

If you swap roller for roller or flat tappet for flat tappet, you should not have to change pushrods. If roller, you can re-use the lifter. If flat tappet, always use new lifters.

If roller, valve springs need to need to generally be heavier (more spring pressures). If going with a smaller cam, roller or flat tappet, spring rate may be too high for either with too high of a rate damaging flat tappet lobes.

You may or may not need a new distributor gear depending on what you have now and what you slip in.

To replace, intake has to come off, pushrods removed, lifters removed, radiator removed (I beleive you can make the swap without lifting the engine out), front of the engine removed. Not a difficult job, but a lot of disassembly. A shop won't be cheap as none are nowadays and you gotta hope they know what they are doing.

With the E-heads, it is possible that you have the 1.65 rocker ratio? You might want to drop down to the 1.5 ratio which will affectively make the cam smaller.

This is all off my head and not knowing a darn thing about your engine - so just use this info for reference and something to think about.


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## Sdpepper (Jun 3, 2021)

PontiacJim said:


> Going to a smaller cam could actually get you in trouble if you don't spec it correctly. Do you know if you have a roller cam or flat tappet hydraulic?
> 
> If you swap roller for roller or flat tappet for flat tappet, you should not have to change pushrods. If roller, you can re-use the lifter. If flat tappet, always use new lifters.
> 
> ...


Thanks Jim. You’ve given me a lot to think about. Appreciate your thoughtful response. I like the car but not the aggressive sound. That’s the price you pay I guess for not buying the car in person and relying on others. I have no doubt others would find the car to their delight. Other than this issue it’s a very nice car. Thanks again.


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## BearGFR (Aug 25, 2008)

Sdpepper said:


> I like the car but not the aggressive sound.


First, make sure the idle mixture is correct. If it's a little on the lean side that can make a car sound like it has a hot cam when it really doesn't. 
It's not difficult. Use a manifold vacuum gauge after it's fully warm, adjust the idle screws equally until you get the highest possible reading. 

Bear


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## Sdpepper (Jun 3, 2021)

BearGFR said:


> First, make sure the idle mixture is correct. If it's a little on the lean side that can make a car sound like it has a hot cam when it really doesn't.
> It's not difficult. Use a manifold vacuum gauge after it's fully warm, adjust the idle screws equally until you get the highest possible reading.
> 
> Bear
> ...


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## Sdpepper (Jun 3, 2021)

Bear:
You were right on! Once the idle mixture was corrected the agressive sound toned down considerably. Thank you again for sharing your expertise.


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