Let me preface w/ saying that I was planning on LT's and X-pipe set up on my new 383 build. That said, I've had a guy at Hedman Hedders give me some mid length headers for $150; I'm at the end of my build and short on cash. Another issue is that the headers are for 92 Camaro. Motor is in car and headers seem to clear everything. Looks like they will run where the stock exhaust was, but won't fit stock. I'll need a custom Y.

Question is, should I use 'em and fab up exhaust (3" all the way back, deleting emissions/cats) or save up and get LT's and run duals? I'm planning on getting a tune ASAP, so I wanted to have the headers/exhaust installed for that. Will it matter much running a good (or decent) custom exhaust vs. stock exhaust for the tune? Will it be worth the money upgrading exhaust over stock for the HP?

Opinions?

 

Yes, you need to upgrade the exhaust from stock at least for a healthy 383....mid-tubes or long tubes or cat back vs. true duals depends on your budget really...and if it's lowered or not. FWIW a custom Y pipe cost me $200 for some pacesetter mid tubes on my 383.

 

Most have the 3" collector which is good. Do you have the part # ? The only issue maybe the ports on the flange not mating correctly. You don't want any restriction at that point.

 

Actually, the ports match up. They are circle ports, not D-shaped, but they will cover the port. They do merge into a 3" collector.

 

Yeah, I just spoke w/ my exhaust shop; guy said probably around $500-600 for a custom 3" all the way back from the headers. Looking at my options and budget, I think I might as well go that route.
I guess I should have stated that I was planning on going w/ 1 5/8" primaries, which I can't find in anything longer than mid length headers. If I did the LT's (1.75" primaries), I'm concerned that may slow down the exhaust flow...not sure.

BTW, it's not lowered; stock height

 

Hell, most of us are running 1.75 primaries on bolt on cars.

While 1 5/8" primaries will work, 1.75 primaries would be ideal for a healthy 383 build.

If you get long tubes, you exhaust guy might charge a bit less considering he doesn't have to snake exhaust up to the mid-lengths, long tubes would be easier

 

That was my logic when I started this build, but my machine guy said that he's had better performance w/ smaller primaries than larger. I thought I was going small enough w/ 1.75", so I was a little shocked when he recommended 1.625" primaries. It's a DD, so it may not matter that much; it's not like they're tuned headers/exhaust anyway
And if I did LT's, I could prob build the exhaust myself if I did all bolt on stuff.

 

Just go to eBay get some v-band flanges and v-bands and a tight x-pipe have the flanges welded to the headers then have a muff shop bend and weld the rest all together.. $500 is too high unless they are using stainless and a mandrel IMO.. Get ur parts then get an estimate.. Make it clear that lowest price gets the job
Got mine done from my LTs to the axel for $250 including shop charge,x-pipe,2 flange/band kits,
& 2 resonators welded directly on the x-pipe then dumped.

 

If the "midlength" read shorties are 1 5/8ths they will be marginaly better than the manifolds, as said pay attention to the outlet of the headers, 2 1/2 inches bad 3 inches good.
Since these are free you really can't complain, people have already had some nice advice on how to run them down to an X and through some duals. I do see you leaving some power on the table with them.

 

Add 20" of 3" to the collector before reducing it down to 2 1/2" and run the X pipe through a pair of Magnaflows just as you planned. You'll produce as much power as any longtube. Use a smooth transition piece from the 3" to the 2 1/2". I run the same setup with a very short tube and gained 17 rwhp and 16 tq on the dyno with simple bolt-ons. The dual 2 1/2" is rated for over 500 hp.

 

Good idea. That might work

 

They are 3" collectors, mid length, not shorties. I'll be running 3" from the collector to either an ORY or X set up. For the price, it's hard to beat. Probably not as good as a good, ceramic coated LT, but should get me close.

 

ok; It seemed like a tight X pipe would fit better, thanks for confirming. I'll talk to the guy again b/c he mentioned getting the 3" pipe. I assume it was aluminized steel, not stainless, and he would be bending. He did say that bending wouldn't be a problem until the 120 degree over the axel, if I run a single. $500 does seem high, so I'll have to go over that with him.
An option still on the table for me is to fab the exhaust myself; just by the bends and make cuts, then weld together...I'm just worried it would look like a kindergardener did it or take me 2 years to finish it, or something! lol

 

If they are true mid-lengths with primaries longer than 10 -12 inches then its quite a good step better than the manifolds. Also the extended collector like mentions will do wonders to the set-up.

 

yeah they're longer than 10-12 inches. I'll plan on doing the extended collector.



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