Header/exhaust decision...

[4Speeds4Ever]

Hey guys,

Long time lurker, first real post on this forum. I have an '81 Calais with a 260 - and as all you fellow 260 owners know, it has to go. I bought a 1970 Olds 350 from a reputable friend who knows his stuff - it's a clean mild build that will be tons of fun for a cruiser and will perform head and shoulders better than the sad, sad little 260.

So I've gone G-bodies with SBCs before...but any SBO-powered G-body that's anything other than stock is breaking new ground for me.

This motor will come with one of two sets of headers - Hedman shorties or Flowtech full-length. Since I'm on a severe budget, I really don't have the dough to drop on a custom exhaust. If I had my druthers, I'd run the Flowtech headers and get this kit from Summit: https://www.summitracing.com/parts/wlk-89017, which should work with a couple of mufflers (which I have) and some header reducers. I can do all this work myself, I ain't scared. However, though I had good luck with Flowtech headers in my old '85 Cutlass SBC 4-speed car, I've read vague horror stories about Flowtech's product in my application. Does anyone have any specific details on how well they work with a SBO in a Cutlass?

If I get the Hedman shorties - which I suspect are higher quality - I'll have to have some sort of downpipes fabbed up - does anyone have experience with these shorties in a G-body/Small block Olds setup?

Exhaust clearing the crossmember isn't an issue here; I will be fabbing a notch in the existing crossmember so that's not a problem.

Long story short - anyone here who's been there, done that have any anecdotes, advice, or cautionary tales with these specific mentioned parts?

Thanks in advance! -Drew

 

[DoubleV]

Experience has shown that anytime one uses cheap headers you're taking a big gamble on fitment. Flowtechs are bottom of the barrel headers. That may fit OK, they may fit horribly ( after you bash em up with a hammer ).

I have heard the Heddman shorties have fitment issues on the driver's side in a Gbody.

As for your choice in exhaust piping, I have no experience in that kit but be prepared for fitment issues with that as well. Universal kits usually don't fit like a glove...

 

[fleming442]

Speedway offers this: https://www.speedwaymotors.com/Univ...xhaust-Mandrel-Bend-Kit-2-1-2-Inch,36340.html
It's not aluminized, but that makes it easier to weld. I bought one recently, and will have parts left over. I think you could get a better fit this way.

 

[4Speeds4Ever]

Unfortunately, I'm, not set up to weld. It's the clamping life for me!

 

[pagrunt]

Do a search for threads, there have been a few on Old headers & manifolds awhile back.

 

[2nd82H/O]

has anyone seen these , they look pretty good

 

[403Olds]

I've had the hedmans that fit well. personally wouldn't bother with shorties.

 

[olds307 and 403]

has anyone seen these , they look pretty good

They have good reviews, are stainless but you would have to contact Thornton's, looks like they sold out of them. They run the early down Oldsmobile down pipes, Pypes sells them separately, just look up for a 455 from 68 to 72. The Hedman's will fit the G body but the steering shaft is tight, I think the cover needs removed. To be honest, the steering shaft had more room on my G body than my A body with my Sanderson shorty headers, barely cleared. Of course everywhere else, there about twice the room compared to my 88 Cutlass. I am thinking of trying a set of the Hedman shorties on my 70S, I wonder if the steering shaft will be an issue.

 

[olds307 and 403]

The Hedman full length are only slightly more than the poor fitting and instant rusting Flowtech's.

 

[MrSony]

Thornton Manifolds are always an option...
http://thorntonmusclecars.com/product/thorntons-350-jr-exhaust-manifolds