Header & Exhaust recommendations please

[furdaddy]

I've been having backfiring problems with my '74 K5 lately, which blew up the brand new muffler. I think part of the problem is the huge crack in the exhaust manifold pulling oxygen into the exhaust stream.

So, next week I'll be having headers installed. The motor is a crate 350, 2bbl carb, not sure of any more details than that. Any recommendations on what to get header-wise?

At the same time, I think I'll have the two auxiliary gas tanks removed to make way for dual side exhausts. Any thought on the pros and cons of this concept?

Any muffler advice?

What about having a crossover installed just behind the collectors? Worthwhile?

Thanks for your words of wisdom,
Jason

 

[BlazerGuy]

Why not do it yourself, it ain't that hard. Duals are a waste of money IMO. Unless you require duals(big HP mill) don't get them. /forums/images/graemlins/grin.gif

 

[K5Chris]

i have dynomax ceramic coated headers, true 2.25" duals, 2 magnaflow cats, and 2 flowmaster 40's with dumps. i love it. an H-pipe behind the headers will improve your low end, and an X-pipe will improve mid-high end. i'd reccomend staying with 2.25" pipes if yer going dual, unless you want more high end, then, get 2.5". flowmasters will give you great low end and a nice loud deep tone. magnaflows will give you better high end, but arent as loud, and dont have the flowmaster tone. if your going with flows or magnaflow, order them from performancepeddler on ebay, they are cheap.


p.s. and yes, my tbi 350 IS a big HP mill /forums/images/graemlins/rotfl.gif

NOT!..... but, i do know for a fact that the headers/duals improved both my low end and the high end.

 

[furdaddy]

[ QUOTE ]
Why not do it yourself, it ain't that hard. Duals are a waste of money IMO. Unless you require duals(big HP mill) don't get them. /forums/images/graemlins/grin.gif

[/ QUOTE ]

Because I have the money to have it done, but not the time, tools or know-how to do it myself. Plus, I'd rather spend my weekends wheeling, not working.

Thanks for the advice on the duals. So people just get 'em for coolness' sake?

 

[mrk5]

I actually posted a question about Thorley Headers on the Garage forum. I'm getting quite a few positive comments about them. As noted there, they are pricy, but it sounds like maybe they're worth it. /forums/images/graemlins/thumb.gif

 

[fjleiter]

Not to mention if you run a single exhaust with 3" pipe it will flow more a 2.25" pipe (area of a 2.5" pipe is only 3.9" while area of a 3" pipe is 7") which puts you close to the 7.8" of a dual setup but removes the necessity of crossover and extra muffler etc...

[ QUOTE ]
Why not do it yourself, it ain't that hard. Duals are a waste of money IMO. Unless you require duals(big HP mill) don't get them. /forums/images/graemlins/grin.gif

[/ QUOTE ]

 

[K5Chris]

i like my duals because i do not have a cross-over. it all goes straight back, and puts both banks at equal lengths, rather than have one bank go straight back, and the other having to cross-over.

 

[rjfguitar]

Ive had both a single exhaust setup and my current Hooker long tube headers, 2.5" pipe, dual 40 series flowmasters, and dual 5" tips. No crossover. Both with my built 406 and I can tell you that I gained more power from my current dual setup. I don't run catalyctic converters either and it sounds extremely aggressive and very loud at WOT.

 

[Paxx]

The point to running true duals is that it is the only way to completely tuck your exhaust up and out of the way of eveything. If you run single or even add a cross-over pipe the y-pipe or cross-over will be a low hanging point on your rig. When it gets smashed up on a rock you can bet it won't flow as well as a dual set-up.

You can have the cross-over behind your tranny/t-case but it should be as close to your collectors as possible so in my opinion it becomes fairly pointless.

 

[socalblazer]

I just added a new exhaust to my 75 and ran dual 2" into a single 3" using a single 3" big block Flowmaster. It sounds really good, but not too loud. Low end power is better but high end dropped off a little. I stuck to the stock exhaust manifolds to prevent any gasket leak/starter/AC bracket issues; all things to be considered if changing from stock to headers. Works great for me! Good luck

 

[Z3PR]

I would go with Thorley TRI-Y's and 2.25" dual exhaust with Flowmasters. /forums/images/graemlins/deal.gif