I'm currently using an H pipe with Edel shorty headers.

Can I expect any real gain changing from an H pipe to an X pipe?

How much gain could be expected going from shorties to true equal length long tubes?

 

No... http://www.mustangexhaust.com/tech/HvsX/HvsX.htm

 

Na, no noticeable gain going from H to X.

 

Thanks for the responses.

Let's take this a little further.

Gutted cats vs sleeved cats.

Same diameter, collector to tip, vs reduced diameter after mufflers.

 

Heres a link to a good article explaining the basics of headers, and is useful for your shorties versus long tubes question:-

http://www.ssheaders.com/header.htm

 

That is an awesome article. For some reason, I was always under the impression that long tubes were better for hp and shorties for torque. I may have to re-evaluate going with the long tubes

va454,

I've always heard that simply gutting a cat is not the way to go, because it can disrupt the exhaust flow. To pass the visual side of the smog check, a buddy of mine grabbed a junkyard 3" cat, gutted it, and ran a 2 1/2'' pipe through it to match his setup.

 

You wasted money on those shorty headers. Shorties are good for full race applications (In my opinion). You have a Big Block.
And its probably in one of those SS454 silverados unless other wise. Big blocks make such easy power its not funny. I'd definately go with Long tube headers. Standard size diameter. Now H-pipe, or X-pipe style exhaust doesnt really matter. You will not feel the difference between the two. But definately go with a true dual exhaust. That and the headers alone will wake it up. If this is in a sliverado then H-pipe is the way to go cause there isnt much room for anything else. Next buy an after market intake manifold. That will help even more. THIRD, I'd match port the exhaust. That right there will create gobs of torque. The exhaust ports on the heads where the headers meet, get it match ported to the headers gasket. Other than that the only other simple trick to do to increase power would be to buy a TBI kit that increases the CFM on the stock TBI. Hope this helps.

 

He did not waste his money. His truck will put any 3rd gen f-body tbi to shame-well except for mine.

Personally, I think you did it right va454. You are at the point where every little bit counts now, as all of the major mod, less a supercharger or no2, have been covered. The X pipe will work better than a H pipe. And sleeving the cats is basically running a straight pipe, but with the looks to keep the cops and visual police happy.

Long tubes vs shorties is still kinda up in the air, but regardless, edelbrock shorties are still a good choice.

Also, va454 has a 2.2" TBI, and a 7060 ecm to power it.

I do like the idea to port match the exhaust.