Trick Flow DHC 175 Stock Compatibility
Thread Starter
Intermediate
Joined: May 2024
Posts: 48
Likes: 5
From: San Jose, CA
Trick Flow DHC 175 Stock Compatibility
I am preparing to order a set of Trick Flow DHC 175 heads to replace the current burnt up 487 heads. I would like to preserve the stock appearance on my 71 which has the factory side pipes installed.
Are the TF DHC head exhaust ports in the same location as the stock 487 heads? Will the location/positioning of the stock exhaust manifolds when mounted to the TF DHC heads be identical to the exhaust manifold positioning when attached to stock 487 heads? In other words do they support proper stock location/positioning of AC compressor and alternator mounting. (Also will the stock side pipes properly attach to exhaust manifold without modification?)
Please let me know if there are any differences from the stock 487 heads that are worth noting.
Thank you!! Daniel
Are the TF DHC head exhaust ports in the same location as the stock 487 heads? Will the location/positioning of the stock exhaust manifolds when mounted to the TF DHC heads be identical to the exhaust manifold positioning when attached to stock 487 heads? In other words do they support proper stock location/positioning of AC compressor and alternator mounting. (Also will the stock side pipes properly attach to exhaust manifold without modification?)
Please let me know if there are any differences from the stock 487 heads that are worth noting.
Thank you!! Daniel
Le Mans Master
Joined: Oct 2010
Posts: 6,938
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
There could be slight differences in accessory mounting locations, but nothing everyone hasn't overcome.
The obvious question is why would you put better flowing heads on your car and choke them down with stock exhaust manifolds? If you do that just have your stock heads redone.
The obvious question is why would you put better flowing heads on your car and choke them down with stock exhaust manifolds? If you do that just have your stock heads redone.
Race Director
Joined: Nov 2006
Posts: 13,258
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Or go with aftermarket 2 1/2 inch manifolds, a bit of a compromise perhaps. And yes a bit of fab work on the exhaust.
But come on, there are no factory side pipes for a 71, so truthfully, the sky's the limit!
But come on, there are no factory side pipes for a 71, so truthfully, the sky's the limit!
Thread Starter
Intermediate
Joined: May 2024
Posts: 48
Likes: 5
From: San Jose, CA
There could be slight differences in accessory mounting locations, but nothing everyone hasn't overcome.
The obvious question is why would you put better flowing heads on your car and choke them down with stock exhaust manifolds? If you do that just have your stock heads redone.
The obvious question is why would you put better flowing heads on your car and choke them down with stock exhaust manifolds? If you do that just have your stock heads redone.
Race Director
Joined: Nov 2006
Posts: 13,258
Likes: 7,848
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Those aftermarket heads are just leaps and bounds better than the factory heads. No matter how much you spend on them.
A can of paint and very few people will spot the aftermarket heads. As far as accessory mounting goes. I had no trouble with mounting the alternator or air-con compressor that a washer or 2 didn't solve with my Edlebrock heads.
A can of paint and very few people will spot the aftermarket heads. As far as accessory mounting goes. I had no trouble with mounting the alternator or air-con compressor that a washer or 2 didn't solve with my Edlebrock heads.
Thread Starter
Intermediate
Joined: May 2024
Posts: 48
Likes: 5
From: San Jose, CA
Those aftermarket heads are just leaps and bounds better than the factory heads. No matter how much you spend on them.
A can of paint and very few people will spot the aftermarket heads. As far as accessory mounting goes. I had no trouble with mounting the alternator or air-con compressor that a washer or 2 didn't solve with my Edlebrock heads.
A can of paint and very few people will spot the aftermarket heads. As far as accessory mounting goes. I had no trouble with mounting the alternator or air-con compressor that a washer or 2 didn't solve with my Edlebrock heads.
Intermediate
Joined: Mar 2024
Posts: 35
Likes: 4
From: Melbourne
I am preparing to order a set of Trick Flow DHC 175 heads to replace the current burnt up 487 heads. I would like to preserve the stock appearance on my 71 which has the factory side pipes installed.
Are the TF DHC head exhaust ports in the same location as the stock 487 heads? Will the location/positioning of the stock exhaust manifolds when mounted to the TF DHC heads be identical to the exhaust manifold positioning when attached to stock 487 heads? In other words do they support proper stock location/positioning of AC compressor and alternator mounting. (Also will the stock side pipes properly attach to exhaust manifold without modification?)
Please let me know if there are any differences from the stock 487 heads that are worth noting.
Thank you!! Daniel
Are the TF DHC head exhaust ports in the same location as the stock 487 heads? Will the location/positioning of the stock exhaust manifolds when mounted to the TF DHC heads be identical to the exhaust manifold positioning when attached to stock 487 heads? In other words do they support proper stock location/positioning of AC compressor and alternator mounting. (Also will the stock side pipes properly attach to exhaust manifold without modification?)
Please let me know if there are any differences from the stock 487 heads that are worth noting.
Thank you!! Daniel
Thread Starter
Intermediate
Joined: May 2024
Posts: 48
Likes: 5
From: San Jose, CA
The TrickFlow DHC heads are set up to emulate the looks of the double hump heads but they surpass them in terms of performance. They should fit straight on and you can get them with or without accessory holes. The exhaust mounting position is the same. The only thing that is different is that they have a taller mounting flange where the rocker covers sit. This allows you to use roller rocker with the original low profile covers. The assembled versions come with valve springs for mechanical flat tappet cams or roller cams. You'll need different springs if you are running a hydraulic flat tappet cam.
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Le Mans Master
Joined: Mar 2004
Posts: 7,502
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From: Little Rock AR
If you use a wider rocker arm you may need to modify your valve cover baffles to suit. The head bolts and different length pushrods will likely need to be replaced from stock with custom aftermarket pieces. Short poly locks might be needed.
I have raised rocker cover rails on my heads and the stock finned valve covers still cleared most of the accessories. The EGR valve would not clear the higher valve cover position. I just removed it and blocked that off so no issue for me. A/C compressor, cruise control, etc cleared.
I have raised rocker cover rails on my heads and the stock finned valve covers still cleared most of the accessories. The EGR valve would not clear the higher valve cover position. I just removed it and blocked that off so no issue for me. A/C compressor, cruise control, etc cleared.
Intermediate
Joined: Mar 2024
Posts: 35
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From: Melbourne
I can't be sure on this particular combination. There are no issues with the stamped steel rocker covers on my 327 with these heads and roller rockers. If I remember correctly the internal dimensions between aluminium finned and stamped steel are the same but I can't be 100% sure. I'll try to check as I have a set of both sitting in the garage, one of which will end up on the 383 for the C3. Haven't quite decided.