I was very impressed with DOUGS headers

[grumpyvette]

I just spent 5 hours removing the old stock exhaust system from my brother-in-laws 1974 big block corvette and replacing that with the side exhaust headers for the big block engine from DOUGS HEADERS, now I lost count decades AGO ON HOW MANY SETS OF HEADERS IVE INSTALLED, BUT I WAS VERY IMPRESSED WITH THE FIT, FINISH, AND OVER ALL QUALITY OF THOSE DOUGS HEADERS, PLUS THEY INSTALLED VERY EASILY, IN FACT I CAN,T REMEMBER A SET OF HEADERS INSTALLING WITH ZERO PROBLEMS BEFORE, these DID !, in most cases theres at least minor things that need to be adjusted or parts or accessories that cause problems. with the install. now I will point out to be fair that there is not much plug wire clearance on a couple locations so youll most likely need too use ceramic spark plug boots,

keep in mind I have trouble getting up and down off the mechanics creeper due to some serious previous injuries,so that is a huge factor in why it took that long to do the job and that alone slows me down a good deal.
yes I have a lift and ( 6) 12 ton jack stands ,I set the (4) 12 ton jack stands I used,

to support the corvette,so the stands on nearly the highest lockable height, would provide a good deal of useable room so I could use a mechanics creeper for access, I used the stands, because I found the lift arms on my 2 post lift would prevent or at least make it more difficult to install the side mount headers,without jack arm lift extensions,installed, so I used the lift to lift the corvette up and then slid the extended jack stands under the car, and lowered the lift so the car sat on the stands and the positions the (4) 12 ton jack stands under the cars front frame and rear differential leaving the side access far clearer, this allowed me to install the headers on both sides from below with zero issues,I used a few feet of 12 lb mono-filament fish line to tie the exhaust gasket in place to the header flange, to make installing the gasket far easier..I then used the supplied small head ,header bolts and a 3/8" ratcheting wrench on the bolts .
AND for anyone thinking its just the car, thats easily fitted with headers and not the brand of headers, used..its the headers, I recently installed headman headers on a very similar 1970 big block corvette, while they went on and fit the quality, fit and finish was not even comparable, but then the cost difference was significant also, the dougs headers with side pipes were chrome, and had 2.125" tubes and cost about $1700
the headmans were just painted black , much shorter and smaller diameter 1.75" tubes,and they exited under the car and had no side exhaust but cost about $350

I guess thats why theres several brands available, Ive got HOOKERS on my corvette, and I used HOOKERS on my last C3 big block corvette and my 1969 race car,and 1968 racing corvette, and while they are a quality part and fit and run just fine, I looked at both sets and while close I think the DOUGS in this particular case or application, are a bit nicer. the only criticism I have is that the ignition wire/spark plug clearance on two of the drivers side plugs is minimal, requiring shorter plugs and/or burn proof ignition wire and plug boots, HARDLY UNIQUE TO THESE HEADERS

http://jbaheaders.com/dougs/detail_long ... ?id=D381-C

viewtopic.php?f=56&t=4541&p=13522&hilit=header+bolts#p13522

viewtopic.php?f=56&t=4541&p=12105&hilit=header+gasket+exhaust#p12105

viewtopic.php?f=56&t=3107&p=8291&hilit=header+gasket+exhaust#p8291

viewtopic.php?f=80&t=7323&p=24881&hilit=side+pipes#p24881

viewtopic.php?f=56&t=2350&p=6204&hilit=exhaust+restrictive+dougs#p6204

viewtopic.php?f=56&t=9296&p=35280#p35280

viewtopic.php?f=56&t=1045&p=1950&hilit=header+gasket+exhaust#p1950

viewtopic.php?f=56&t=3155&p=37050&hilit=side+exhaust#p37050

http://jbaheaders.com/dougs/detail_exha ... ?id=D930-C

 

[grumpyvette]

BTW C3 corvettes require a set of (T) bolts that fit in recessed slots in the frame under the side rocker panels that are used to support the side pipes , you can buy then from hooker, dougs, summit racing or jegs,
OR if you have a belt sander and or grinder, you can Buy 4 carriage bolts at the local hardware (I think I used 3/8” STAINLESS AND FENDER WASHERS, bolts). File 2 flats on the head , of each carrage bolt, so it fits through the slot in the frame, one on each side, and you have a “T” bolt. Buy the rubber washers their too.

http://www.pertronix.com/prod/new/details.aspx?ID=142

http://www.summitracing.com/parts/HOK-65668XHKR/

theses at least a dozen different muffle insert designs available, most are effective at reducing sound levels but most also restrict exhaust flow rates in the upper rpms making the power seem to hit a wall at some rpm level obviously dependent on several factors like cam, gearing engine displacement etc, most cars have an obvious power improvement if you remove the muffler inserts at the track.

good related info

viewtopic.php?f=56&t=495&p=25975&hilit=side+exhaust#p25975

viewtopic.php?f=56&t=260&p=315&hilit=side+exhaust#p315

viewtopic.php?f=80&t=793&p=1150&hilit=side+exhaust#p1150

 

[grumpyvette]

well hes had the DOUGS headers on the big block 1974 corvette for a few months and his engines basically stock and they still look and sound great and there was a very noticeable increase in power once the slide in muffler inserts were removed from the side exhaust at the track, so the headers work well,
the only issue so far is that cylinder #3 has the spark plug wire located so it REQUIRES the ceramic strait plug boot and the heat resistant sleeves on the plug wire to prevent the ignition wire from slowly deteriorating from the header heat levels, so we purchase a full set and installed them on all cylinders.
now most header designs have one or more cylinders that have spark plug clearance issues and having only one cylinder close to the plug is better than most.
standard strait plug boots would work on the other 7 cylinders but #3 is just a bit to close for it to last without protection.
keep in mind aftermarket heads will have the plug location and angle be different so the problem might be worse or totally eliminated so do some research and try to find out what previous customers have found and used, every application might be different, and just because a set of headers works well or has problems with one combo doesn,t indicate it will be free or or plagued with issues on a different application. but obviously some brands will tend to far better than others in clearance, fit and quality

grumpy, who makes a really good quality header for my car?

I get similar questions all the time, and there ARE certain brands that do have a reputation for better fit and finish on headers,
but your results are totally dependent on you doing accurate ,prior research, your asking the correct questions,
knowing exactly what cylinder heads your using,and yes better quality tends to cost more than bargain basement prices!
knowing exactly what car it will be installed into and if your dealing with a better quality manufacturer helps.

http://www.superchevy.com/how-to/148-0404-best-headers-shootout/

http://www.lemonsheaders.com/

http://www.stahlheaders.com/

http://www.stainlessheaders.com/

http://stainlessworks.net/products/performance-systems/headers

http://www.burnsstainless.com/

https://www.carid.com/performance-headers.html

 

[philly]

were using those accel ceramic boot plug wires on the callaway only because the manifold temperatures get pretty extreme when the car is hot lapped, im pressed with the design and quality of those things and they arent terribly expensive either.

 

[grumpyvette]

we have been using those ceramic spark plug boots and heat reflective sleeves ,out of necessity on his 1974 big block engine, corvette as one of the drivers side plugs and the plug wire are close enough that the radiated heat quickly melts most ignition wire without there use, the wire does clear the header tube and it certainly looks like its close but acceptable, in clearance but like most big block and some small block cars routing the ignition wire so heat will not cause problems with durability is a bit of a challenge.
that's certainly not a fault or limited to DOUGS headers as they seem to be better than most designs but it is something you need to be aware of.