JBA vs Doug Thorley Header

[BcurpKodiak]

Hello all,

I know there has always been plenty of discussion on header/headers on every engine imaginable.

I am specifically interested in these 2 headers. 4.7L Stroker, ported/big valve edelbrock head, 68mm TB, 68-235-4 comp cam from Russ on 114*

I am not your average Jeep guy. I am scrutinizing every little pound in my jeep keeping it as light as reasonably possible. I am also trying to make as much power as possible with my stroker build. It's a ground up build, so no reason not to do it to my liking now.

Does anyone know if there is a difference in power between those 2 headers? I would choose the Doug Thorley if they were the same price. But the JBA is $200 less.

I'll be running the header open most likely, or with a magnaflow race muffler on the end of it. I plan to modify whatever header I purchase so that it has a 3" outlet.

EDIT: I have also been interested in the clifford header and even made a thread about that a while ago. My interest in the 2 headers above has to do with being able to order them on Amazon with free shipping. I live on an island in Alaska. Would the Clifford possibly make more power than the above 2??

[BcurpKodiak]

One other concern that makes me lose interest in the Clifford header is no bung for O2 sensor, and where would I put it anyway? In one side and hope that's accurate enough only seeing 3 cylinders?

[jsawduste]

Have the Thorley and consider it a very good piece. Lifetime warranty to boot.

Having said that..........The 7120/0630 #4 exhaust primary tube WILL interfere with the late model horse shoe intake manifold..........

Milled the hump off the bottom of the intake plenum but still had to dimple the primary tube a touch.

Cant say what fitment issues you may run into with the JBA.

[BcurpKodiak]

Have the Thorley and consider it a very good piece. Lifetime warranty to boot.

Having said that..........The 7120/0630 #4 exhaust primary tube WILL interfere with the late model horse shoe intake manifold..........

Milled the hump off the bottom of the intake plenum but still had to dimple the primary tube a touch.

Cant say what fitment issues you may run into with the JBA.

Thanks that's some pretty good insight

[SkylinesSuck]

I had no such issue on my JBA headers with the newer style intake, but I got the newer style dual outlet manifolds.

[jsawduste]

I had no such issue on my JBA headers with the newer style intake, but I got the newer style dual outlet manifolds.

[BcurpKodiak]

Interesting. I thought about using the newer style header, but I'm pretty sure I can't with the Edelbrock head.

[SkylinesSuck]

You can. You just can't use the newer style stock manifolds as the ports are much smaller like on a stock 0331 head from the same time frame. Aftermarket headers have larger ports and can be used on all heads. That's how I understand it at least. You will of course need new exhaust piping fabed up after the manifolds.

[SkylinesSuck]

I had no such issue on my JBA headers with the newer style intake, but I got the newer style dual outlet manifolds.

Yes, exactly my point. That's why I specified. He hadn't specified which up an until this point, and I was saying Doug Thorley is an option, but you'd have to get one designed to clear the intake manifold you plan to use.

And OP, one thing I forgot to point out is the Doug Thorley ones are ceramic coated from the maker. The outlets on mine were a little small for my liking and the primaries weren't huge either. I think they matched the ports on the head though. I posted up some pics and stuff in a thread on headers not too awful long ago about it.

[SkylinesSuck]

viewtopic.php?f=5&t=5298

[BcurpKodiak]

Does the newer style header make better power than the older style?

https://afepower.com/afe-power-48-46202 ... el-headers

Edelbrock's site says (for the head): This head is NOT compatible with 1999-2006 OEM exhaust manifolds.

But: Most aftermarket exhaust headers are compatible, but please check with the exhaust header manufacture to verify.

[BcurpKodiak]

Well I bought the Doug Thorley. All of a sudden right before my eyes, the price dropped (on amazon) over $200 to where it was like $2 cheaper than the JBA. There was only one left in stock and I got nervous they were just trying to get rid of it, and maybe not get anymore.

It took me a while to realize it has larger 1 5/8 primaries, which makes a difference for me. I'll end up cutting the collector to make it a 3" outlet.

[SkylinesSuck]

Picture review when you get it!

[BcurpKodiak]

I was wrong in my last post. I thought I saw somewhere the DT header had 1 5/8" primaries, but then saw it as 1 1/2" elsewhere.

I'd love to post pics. I was using photobucket and those turd nuggets are charging for photo sharing now. Ruined most threads on all the forums I use!!!!

And they want way too much money! What's another good way to post pictures??

[SkylinesSuck]

Let me know when you find out :/