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.

.

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.


.


.

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

.

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.

No major issues with them on my 67 GTO. Liked them much better than my Hookers!

Can you post something that shows what you did to make the Z bar work? Did you keep the zerk fitting installed?

i don’t have pictures i just cut lower arm off zbar moved it over and rewelded it so it didn’t hit header tube

I forgot about this thread. I installed these headers a few months ago and the fitment was terrible!!! They hit the frame everywhere. I had to hammer on almost every tube to get them to fit and dent the frame in one spot above the pass side engine mount to get them to fit. And even now with all the hammering one tube on the drivers side hits the frame. Drives me nuts but the only way to fix it is to pull the driver slider header which means pull the engine again. I had to trim 1/2” off the drivers side lower A arm rear mount. And I had to cut the header flange between cyl 2 & 4 because there is no way to get the header up over the dip stick.

Here’s some pics. Nothing like hammering on a $1k set of headers….. very unhappy with these headers. Only good thing is they don’t hang low.

Doug's header fitment D567 on 67 GTO
 

I have the spacers installed, without them, there is no way these fit! I have to dent #6 tube this afternoon to have clearance to install the gasket!

I have all new poly bushings on frame and A arms. Also, frame isn't bent. Installing these have been a miserable experience!!

My original D567 from 1974 are 1 3/4" tubes and 3" collectors, and the #6 tube was changed on the newer set causing the fitment issue!!

They fit perfect BUT the instructions are a lie. If the engine is out they have to go in first. If it’s in then you gotta take both motor mounts loose and bring it way up. If you have a factory bellhousing it may be better. I have QuickTime with starter bubbles on each side

I would suggest that you get the headers un coated and fit them as needed.
Then have them jet hotted.

Putting the pretty ceramic coating on first and then massaging them creates issues.

I also have a 67 with Doug's. They are the best header for sure.

PS. You will need lots of beer to help you install them. Small children should be out of earshot too.

Sent from my SM-G930V using Tapatalk

Doug's header fitment D567
 

My fridge isn't big enough for the beer needed!! As I said #6 tube is the issue not enabling the engine to sit properly.

This is what I always do. Get them uncoated, test fit, install O2 sensor bungs and coat.

Fitment
 

I have Doug's D port on my Kaufman heads, clearance is good, glad I got new engine mounts and some custom spacers that fit under the mounts.

Those headers are destroyed! Are those D or rd. ports? I run 2" rd. port Super Comp in a 70 A frame. Other than a minor #6 tube frame scraping over bumps. The fitment is great and the oil filter is easily accessible. I did cut the header brace between #2 and 4 for easy oil dip stick tube access.

I’m running RP Edelbrock heads with Dougs headers and I have no fitment issues. I also use a Wix 51258 or Baldwin B39 with a QuickTime scattershield and I can get them in and out fairly easy