# Installing Dougs headers D567 plus engine swap, 66 Lemans



## danford1 (Nov 15, 2016)

Hi, I'm new here, in fact this is my first post.

I'm an old fart and have been working on cars and building engines since the 60's.

I'm currently doing an engine swap and other things to a 66 Lemans. Out with the 326 and Power Glide and in with a 428 and 200R4 with new shifter etc. Also new Dougs D567 headers. The car has PS, PB and A/C.

I'm just getting started on the engine pull. This is the first Pontiac I'm doing as I have always done Ford cars.
Sorry, I know that is frowned on, but it is true. The big difference is shock towers vs no shock towers.
I was looking at the tiny amount of clearance there is to the suspension. I'm looking for pointers on what to do and not to do to make this go as easy as possible.

I've been reading old posts and the Dougs seem to fit the best but no one explained the procedure.
I mean do you have to lift the engine off the mounts to get at the bolts on the stock cast iron manifolds? Do the headers actually slip in from the bottom? How the heck do you get the bolts in them?

I know I'll be pulling the engine and trans together and not removing the stock manifolds, but, I still would like to know how you guys put headers in these cars.

Is it possible to bolt the headers to the engine/trans while it is out of the car and drop it into the car with the headers on? I've done that on other cars, just wondering if I could do that on the Lemans.

Just looking at the bolt locations an angles makes my back hurt...
I know it would be easier if the fenders and wheel wells were removed but I don't want to do that. This car was restored and the panels fit fine. I don't want to risk chipping the paint. Plus I work alone, I don't have helpers nor do I have a lift. Taking the front clip off isn't an option either (working alone) I'm old school with floor jacks and jack stands...

Can you fine gentleman give and old guy some pointers, tip and tricks? I hope so 

Thanks
Danford1


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## BearGFR (Aug 25, 2008)

Hi Danford,

Your Doug's headers should have come with some installation instructions ---- I know mine did. Since you're doing an engine swap anyway, the easiest way to do it is to set the headers in place while the engine is out. If that's not an option, then as I recall the installation procedure is to do one side at a time. Support the engine with a floor jack, remove the long motor mount bolt on the passenger side, use the jack to lift that side of the engine to get some room to work, then drop the header in from the top. Lower, re-install the bolt (!), and repeat the process on the drivers side. Getting the flange bolts started and in is tough and you will expand your vocabulary doing it. Be patient and persevere. I'd recommend replacing at least one flange bolt on each end of the head with a stud and nut so you'll have something to "hang" the header on while you're futzing with the rest of the bolts. It might be easier still to use studs for all the fasteners - that way you could slide the header out on the studs with just a few threads showing, providing more room to slip each nut on and get it started.

Other tips. That brake line distribution block you probably have on the inside of the drivers side frame rail --- plan on biting the bullet and relocating it to the top of the frame rail, otherwise you're likely to have clearance problems there and the heat is going to tend to cook your brake fluid. I highly recommend replacing the starter with one of the newer "mini starters" (I really like this one: RobbMc Performance Products - Pontiac Starter It's a quality piece, the solenoid can be 'clocked' to any position you like to get it away from the heat, and the company is great on service and support), otherwise you're likely to find that in order to R&R the factory starter you'll have to loosen the drivers side header. Lastly, pay attention to the lower control arm bolts. If the "nut end" is towards the header you may have clearance issues there - I did. I wound up turning the bolts end for end so that the bolt head is next to the header tube (and it's still pretty tight there). Of course this also means if I ever have to R&R the lower control arms... yeah, the headers are going to have to be moved out of the way first. I see you have a 66 -- if it was a later model with the 'back drive' interlock between the steering column and the transmission, you'd have to either completely discard that and run without it, or spend some time re-bending / re-engineering the linkage to make it fit around the header and still work.

Make sure you use high quality gaskets (I like these: Remflex - Pontiac V8) and don't forget the anti-seize on the fasteners. Yeah, you may have to check and re-tighten them periodically but that sure beats having to deal with a seized one down the road.

Bear


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## danford1 (Nov 15, 2016)

Thank you. If the headers can be bolted on to the engine/trans before I drop it in, that is what I'll do.
I'll at least try it that way. I just pulled the 326 and trans so now would be a good time to test the header fitment provided they bolt up to the 326 heads. I really, really want to just drop this in WITH the headers attached. That was nice when I could do it on a Torino. On my Fairlane I can drop the engine in with the pass side header on but not the drivers side...

Danford1

PS I'll look in the Doug's box for instructions


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## BearGFR (Aug 25, 2008)

One small clarification: When I said "with the engine out" I was thinking of setting the headers into the engine compartment on the sides and then lowering the engine down 'between' them. I've not attempted to install an engine with the headers already on --- but that might work too!

Bear


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## danford1 (Nov 15, 2016)

What a freaking nightmare this job has become. I was finally about to install the 428 in the car today. I figured I bolt the headers up while the engine is still out to see what clearance problem I'll have by the oil filter and starter. No way in Hell these are the right headers. Yes, they have a big D567 stamped in them but the bolt pattern isn't correct. The center two bolt spacing is a couple inches to wide!

Has anyone else run into this problem? The engine has stock iron heads on it , not aluminum.

I emailed Doug's today but who knows when or if they will respond.

Danford1








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## PontiacJim (Dec 29, 2012)

The headers appear to be for the Ram Air IV heads/exhaust ports (Doug's Headers 1 7/8" 4-Tube Full Length _Round Port Headers _Pontiac GTO 326-455 64-72 *D567*). You want the "D" port headers which should be the *D564* for the '64-'67 bodies.


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## danford1 (Nov 15, 2016)

Wonderful... Thanks
I'll check into them.

Danford1


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## BearGFR (Aug 25, 2008)

PontiacJim said:


> The headers appear to be for the Ram Air IV heads/exhaust ports (Doug's Headers 1 7/8" 4-Tube Full Length _Round Port Headers _Pontiac GTO 326-455 64-72 *D567*). You want the "D" port headers which should be the *D564* for the '64-'67 bodies.


:agree: Those are definitely for round port heads (Ram Air IV, 455HO, 455 SD, etc.)

Bear


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## Stuff1262 (Sep 6, 2018)

I was searching for information on Doug’s and wondering how this all worked out for you


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