Doug’s RP header fitment 1967 GTO
 

Im looking at purchasing a set of Doug’s D567 headers for my 1967 GTO. Looking for feedback on how well they fit.

Anyone out there running these?

https://www.summitracing.com/parts/dou-d567

Those are for round port heads. I see in your build that you have 670 d-ports unless you have changed heads since then.

Yes swapping to edelbrock round ports

The reviews on Summit aren't so great.

The Doug's I have fit great on my car, but I purchased them over 10 years ago before Doug's was acquired by Pertronix. I wonder if the quality has changed for the worse over the years?

Doug's header fitment D567
 

I've ran these since 1974, nice fit! I did cut the flanges at the heads to allow easier bolt fitment. If using a regular size oil filter, you have to remove the header completely! Flange bolts and at the head, otherwise you can't remove the filter. It's a mess!
Also, have to move the brake valve that's on the driver's side part of the frame. Install the headers from the bottom, won't go in from the top.

Some people have mentioned banging on them a little to make them fit. The Doug's or the cheaper ones on ebay are your only options anyway. It appears that Ram Air Restorations will likely never have the round port manifolds in stock to fit a pre-'68 car.
I'm not sure of the previous installations, but I'm wondering what size primary tubes they had before. A big problem in my mind is the 1 7/8" primary's.

Same set since 1974? I do wonder how the fit has changed over the years.
I don’t like that about the oil filter…. I have read some similar issues. Should I do a remote oil filter?
Funny you mention the brake distribution block. I have the motor out of the car now and was thinking about moving that thing anyways because of heat.

Summit reviews are hit or miss which make me nervous. I just don’t know of a better header out there

I've run both the D-port and round port on my 67 GTO, and feel the round ports were the easier install with the bolts being easier to get to. Also swapped back to the manual trans from the auto when the round ports were installed and except for moving the zerk fitting on the Z-bar there were no fitment problems.

Both D-port and round port lock in the filter with a scattershield in place, but don't think I had the filter problem with the auto trans, but can't remember for sure. With the scattershield, I do my once a year filter change by removing the filter and adapter as a unit and lifting straight up. It is messy and no fun, but have put up with the hassle. A remote filter wouldn't be a bad idea but it can be added later.

they fit great on my 65 gto. i use the hp2006 k&n filters specifically because that nut on the bottom makes oil changes way easier.

i used half dozen sets of doug’s rd port headers in last couple yrs fit perfect even with manual trans z bar last set about
a yr ago drivers rear tube was a little different from the other sets had to cut bottom lever off z bar an move and reweld

Work great for me and I have an aftermarket bellhousing

I'd like to address the OP, and his dilemma he asks about in his post.

If you put a by pass oil filter on the car, and you can forget about changing the OEM filter. You also get a filter that is many times superior to any style or brand OEM filter made.

I've heard (many times over, and over) that hobby cars don't need a by pass oil filter, but if a situation ever cried out for using a by pass oil filter on a hobby car, this dilemma looks like it would.

The OP suggests a remote mount, that would work, but you'd not realize any improvement in oil filtering quality over the OEM filter, and elbow. If you're going to the trouble to change the position of the filter, it would seem prudent to also improve the quality of the filter, extend the life of the oil, and as a bonus cut the wear in the engine by by roughly 85%. You also gain 1 quart more oil volume by using a by pass oil filter. AMSOIL makes a remote filter that incorporates a OEM style filter, and a by pass style filter in the same remote unit.

I.E. if your engine is currently 6 quarts with the OEM filter and OEM pan, you now have a 7 quart capacity without changing the pan to a larger volume pan.

That designer oil that car enthusiasts like to use is getting quite expensive lately. You can quit throwing it away, and just change the by pass oil filter and leave the expensive designer oil in the car. Unlike using an OEM filter, that only filters 30-40 micron particulate from the oil, it stays clean down to single digit micron particulate removal. You can leave the clean oil in for years, and 30-40,000 miles with a by pass oil filter.

I've been using by pass oil filters on my own LS2 05 GTO, and my 6.5 diesel truck for over 10 years now. They work just as I described them to work. I'm extremely happy with them on my own vehicles.

Just a suggestion for your self described problem, your car, your choice.

Smaller in diameter filters fit .

Thanks for the info guys. Has anyone has to run an 1/8” - 3/16” spacer under the frame side engine mounts to get better header to frame clearance?

This is my third set on a 71 A-body over the last 15 years, and I will never buy them again, switching to super comps.

They needed massaging, and the collectors don't point straight back, making exhaust install a headache. Shoot, the driver's side points so much towards the center of the car the trans selector is so close I had to bend it slightly to clear. No way would the back lock setup work. both hang too low IMO.

The Headmans I had on at one time were better.

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On the firebird, with the Doug's, I had to trim a Lakewood bellhousing to be able to swap the filter without taking the filter housing off. The block plate and bell hang out pretty far, plus there's a starter bump out on the Lakewood.


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My D567 Thorley's from the 70's only have 1 3/4" tubes and alot thinner head flange than the current ones. I think the tubes are now 1 7/8" which would make them closer to the chassis than mine!

Doug's make 1 3/4, 1 7/8, and 2" tube headers.

https://pertronixbrands.com/search?q...engine=326-455

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On my car, no modifications or clearancing was required, the collectors point straight back, and oil filter changes aren't easy but can be done.

I just run a Wix 51258 filter and wrap a plastic bag around the filter so it won't spill oil all over the headers as I maneuver it out.

They are the 1-7/8" round ports.

I ran an older set and they fit well. I know the company changed to Pertronix a bit later. I know a very reputable Pontiac builder and he dyno'd the RA manifolds to headers in comparison and said he saw no difference until and after 550 HP at the crank. Just one builders opinion. I run the RA manifolds on both my 67's. When it comes to ease of pulling the motor and oil changes it's much easier and 4 speeds are more friendly to work on clutches and "Z" bars.