LS Swap headers

[67Rally]

Well, after a few weeks of researching, emailing, PM'ing, three different threads on three different sites...I had narrowed it down between the Dynatech's and the Doug's 3337's. I ruled out the Texas Speed because there just wasn't enough info on them, and I wasn't crazy about the design.

The guys from Dynatech were great with trying to help, but it's the same design as the Texas Speed stuff (still wondering if Texas Speed copied them, or if Dynatech is making their headers).

So I ordered a set of the Doug's 3337's (jwcarguy's pics helped push me to the final decision). My only hesitation was that they look identical to the ebay brand headers that I was looking to get rid of. In fact, when I first got them, I thought they were identical, but there are subtle differences in the tube design (i.e. the guys in China didn't do a perfect job on the knockoff). I installed them this weekend. I ended up moving my engine and transmission about 3/4" back towards the firewall and I'm very happy with the clearance.

ebay Header passenger side:


Doug's 3337 passenger side:


ebay Header driver side:


Doug's 3337 driver side:


Doug's clearance:






Doug's driver side ground clearance:


Doug's passenger side ground clearance:


About 4" of clearance on passenger side, and 4.5" on driver side:

[Vince@Meanstreets]

that looks pretty good, nice fitment.

What engine mounts again?

[67Rally]

Originally Posted by Vince@MSperfab

that looks pretty good, nice fitment.

What engine mounts again?

LOL, I was just going back through the thread to see if I had posted it here.

I'm using the tall & narrow '69 Z28/350 frame mounts (3945507/8) and the tall & narrow Energy Suspension motor mounts (3.1117G). Along with the Dirty Dingo Sliders, and a BMR adjustable T56 trans crossmember.

[Vince@Meanstreets]

Awesome stuff!

[OBeer-WAN-Kenobi]

Glad you found something that fit so nice for you!

Can you do me a favor and see if you can get an accurate measurement to a fixed point for me?

Maybe from the front left bolt on the steering box to a point on the engine; like a header bolt or something? I'd like to see where my engine is sitting in relation to yours.

Really, this is what all of us need from the manufacturers. Instead of telling us that this will fit with such and such mounts (which isn't always guaranteed) they should have measurements of where the engine should be sitting (for their headers) that we can use to compare. The best measurements would probably be off of the subframe or at least something bolted to it.

I'm still waiting on some parts to be powder coated before I put the subframe I re-manufactured back under my car but after that I should be needing to order headers really quick.

[67Rally]

Originally Posted by OBeer-WAN-Kenobi

Glad you found something that fit so nice for you!

Can you do me a favor and see if you can get an accurate measurement to a fixed point for me?

Maybe from the front left bolt on the steering box to a point on the engine; like a header bolt or something? I'd like to see where my engine is sitting in relation to yours.

Really, this is what all of us need from the manufacturers. Instead of telling us that this will fit with such and such mounts (which isn't always guaranteed) they should have measurements of where the engine should be sitting (for their headers) that we can use to compare. The best measurements would probably be off of the subframe or at least something bolted to it.

I'm still waiting on some parts to be powder coated before I put the subframe I re-manufactured back under my car but after that I should be needing to order headers really quick.

I'll try to find a good reference point tomorrow and post back with some measurements.

I installed the driver's side header by removing the engine frame mount bolt and jacking the engine up on that side. When I went to lower the engine after the first attempt, the #5 header was just about to hit the pitman arm before the engine was all the way down. I moved the engine back about an 1" and then #3 was within 1/32" of the PS box. I found a happy medium somewhere in between (I know I said about 3/4", but I didn't actually measure).

The key for me was having an adjustable set of adapter plates (Dingo sliders), along with an adjustable trans x-member.

[OBeer-WAN-Kenobi]

Thanks for the info guys, I appreciate it.

Hopefully in a week or two I'll be putting my engine in my subframe again and seeing where the measurements are. I have to...ehem..."adjust" the frame a bit for the low mount alternator as well so it's probably important that I get a set of headers fairly quickly after the initial check so I can get that going.

Worst-case, I suppose I can just get headers and machine some new mount plates to make the placement work for the headers instead of trying to get headers to work for my mounting location. After all, the plates are just pieces of flat stock with 3 counter-sunk through holes and 3 tapped holes in them anyway. Not like they are difficult to make. I'd just rather I use "standard" modified components, if that makes sense....LOL

[toddoky]

Originally Posted by 67Rally

Well, after a few weeks of researching, emailing, PM'ing, three different threads on three different sites...I had narrowed it down between the Dynatech's and the Doug's 3337's. I ruled out the Texas Speed because there just wasn't enough info on them, and I wasn't crazy about the design.

The guys from Dynatech were great with trying to help, but it's the same design as the Texas Speed stuff (still wondering if Texas Speed copied them, or if Dynatech is making their headers).

So I ordered a set of the Doug's 3337's (jwcarguy's pics helped push me to the final decision). My only hesitation was that they look identical to the ebay brand headers that I was looking to get rid of. In fact, when I first got them, I thought they were identical, but there are subtle differences in the tube design (i.e. the guys in China didn't do a perfect job on the knockoff). I installed them this weekend. I ended up moving my engine and transmission about 3/4" back towards the firewall and I'm very happy with the clearance.

ebay Header passenger side:


Doug's 3337 passenger side:


ebay Header driver side:


Doug's 3337 driver side:


Doug's clearance:






Doug's driver side ground clearance:


Doug's passenger side ground clearance:


About 4" of clearance on passenger side, and 4.5" on driver side:

That's great that something came together for you finally 67rally, seems to work real well for you.

obeerwan- that's a good point you made and in the case of an LS swap 1st-gen F-body/3rd-gen Nova like 67rally has the new Hooker engine mounting brackets for that application position the machined front surface of the engine block 1/2" back from the front wall of the primary engine crossmember. That equates to the typical distance between the back of the passenger side cylinder head and the firewall being 1-1/2". Maybe this info will help others starting this swap.