Generation IV External Engine - lsx 454 into a 67 camaro- headers 1 7/8" or 2"

Hey guys I’ve been doing a lot of digging on headers lately. I will be running a lsx454 from gmpp in my 67 camaro. I have s&p adapters, Lees steering box, and stock frame w/ built in sub frame connectors. I will be getting a magnum t56 for my transmission. I’ve been reading a lot of conflicting information on many different sites as to what size header to run, 1 7/8" or 2". I’m looking to make around 600 at the wheels. I measure the exhaust ports on the heads and they are not even close to 2" so how would a 2" header make that much of a difference? Plus the price to go from a 1 7/8" to a 2" is quit a difference. Opinions? Though?

Here is what I was looking at for 1 7/8"
http://www.dynatechheaders.com/m_camaro_67_69.html

I’ve read some really good reviews on these about quality and fitment and the price cannot be beat for $400.

The cheapest 2" I’ve found are these
http://www.jegs.com/i/Hedman+Husler/502/45110/10002/-1

I don’t know much about them so I’d have to do some digging, priced at around $700.


Thanks for your time and help, Steven

it may not be a huge difference going from 1 7/8" to 2" but you would yield more peak power with the 2 inch. im assuming you are staying N/A? if thats the case then it would be a toss up honestly. you want to squeeze most power as possible or save a few bucks? FWIW dynatech makes really good headers from what i've seen

I would personally run the Dynatechs...or these lol
http://www.detroitspeed.com/1967-1969%20Camaro-Firebird-Products/061001-main-pp.html

it may not be a huge difference going from 1 7/8" to 2" but you would yield more peak power with the 2 inch. im assuming you are staying N/A? if thats the case then it would be a toss up honestly. you want to squeeze most power as possible or save a few bucks? FWIW dynatech makes really good headers from what i've seen

Yep staying N/A for now. Ive been told by a couple people 2" and Ive also been told by some 1 7/8...I think im leaning twords the cheaper route and going with the dynatech as Ive herd great things about them. Plus the price can not be beat.

I would personally run the Dynatechs...or these lol
http://www.detroitspeed.com/1967-1969%20Camaro-Firebird-Products/061001-main-pp.html

haha. It was a toss up between those two actually...lol..:D

I am going to bet you have more trouble trying to hook that car up, than noticing a little bit of potentially lost low rpm torque. I bet the low rpm numbers would be close, and the benefits would be greater with the 2 inch primaries.

With that many cubes.... 2", hands down.....

If nobody can produce any real data showing 2" being substantially better than 1 7/8" I'd go with the cheaper route. Even if they are a handful of HP better is it anything you will ever notice?

The 1 7/8" won't be a detriment unless your motor's really a cammed up N/A or an FI combo. I have 1 7/8" Kooks on a very mildly cammed LS7 in the V and it made 504 at the tire (roughly 580 @ the crank) through converters.

The coated Dynatechs are a good deal. I'm using their 1 7/8" in my 67/LS7/4L80E swap. Plenty of clearance around the steering box area!

You do have to be careful with the plug wires on #5 & 7, as the high routing of the #2 tube put the wires in close proximity. Fabricating a retainer that bolts to the valve cover (and the use of insulators) solves the problem nicely. I've attached a couple of shots (poor quality) to show the #5 & 7 plug wires prior to installation of the retainers.

The only negative that I've found is that if you're using the stock-type motor mount/LS adapter plate combo, the #1 tube won't clear. They're designed for a different motor mount setup.

The 1 7/8" won't be a detriment unless your motor's really a cammed up N/A or an FI combo. I have 1 7/8" Kooks on a very mildly cammed LS7 in the V and it made 504 at the tire (roughly 580 @ the crank) through converters.

The coated Dynatechs are a good deal. I'm using their 1 7/8" in my 67/LS7/4L80E swap. Plenty of clearance around the steering box area!

You do have to be careful with the plug wires on #5 & 7, as the high routing of the #2 tube put the wires in close proximity. Fabricating a retainer that bolts to the valve cover (and the use of insulators) solves the problem nicely. I've attached a couple of shots (poor quality) to show the #5 & 7 plug wires prior to installation of the retainers.

The only negative that I've found is that if you're using the stock-type motor mount/LS adapter plate combo, the #1 tube won't clear. They're designed for a different motor mount setup.

Great advise and info man. Im pretty sure im going to run these headers. For the price I cant be beat. Im not affraid to fab up something clean to hold the wires or need special plugs. I am however worried about the motor mount issue. I have stock mounts/s&p adapters in stock location. If Im reading what your saying right my setup wont work. I can buy new adapters which ones do you have that work? thanks for all the help, Steven