Author Topic: '69Z 302 - current header recommendations please?  (Read 40070 times)

hubleyman

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'69Z 302 - current header recommendations please?
« on: July 25, 2013, 02:56:19 AM »
So I am just about done with rebuilding my 302 for my '69 Z and decided to change from stock exhaust manifolds to headers.  I'd like the car to be louder and a few extra HP never hurts anyone.  After researching all the threads I could find on the subject, it seems prudent to ask the group once again what the current best choices may be based on your experiences.  Every time I see good recommendations, I seem to run across not-so-good ones for the same product.

Here are some specs on my engine:
Bored .020 over with true final 11:1 comp ratio (custom built pistons with no block decking)
30/30 solid lifter cam (Comp Cams OEM replacement)
OEM heads with no porting
OEM intake and carb (upgraded to 72 primary jets)
OEM distributor (set up per CRG recommendations)
Roller rockers and a few reliability upgrades
FYI - The car has OEM power steering.

I also plan to keep the chambered exhaust because it appeals to me.  The car typically gets driven locally mostly / a Sunday-Funday cruiser.  No racing or drag strips, but maybe an occasional slip of the clutch to see if the rear wheels can still smoke a little.

I'm looking for an excellent quality product, that fits properly out of the box, and doesn't require mods for my power steering.  My first inclination is to go with Stahl headers, because they built me a couple of sets for my midyear Corvette race cars and were superb, but I have not used them on a street car as of yet.  Also thought about buying some repro OEM style headers because that would be cool, but they seem to be fairly pricey. I've had Hookers, Hedmans, etc. on my street cars which were fine, but not great.

The rebuilt 302 goes on the dyno soon, so it's about time to order some headers.  Any suggestions or comments, good or bad, from recent purchases?  Any new input would be greatly appreciated.

Thanks!  Charlie

ZLP955

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Re: '69Z 302 - current header recommendations please?
« Reply #1 on: July 26, 2013, 10:04:37 AM »
Charlie, interesting to see what others recommend, but I have heard good things about Doug Thorley Tri-Y headers, especially regarding underside and engine bay clearances, so will be getting those for when I reassemble my car.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway

Kelley W King

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Re: '69Z 302 - current header recommendations please?
« Reply #2 on: July 26, 2013, 12:21:38 PM »
I would love to hear chambered pipes with a set of Mickey Thompson Super Scavengers but good luck trying to find a set. I run Hookers on my cars until I find the MT SS.
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hb1

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Re: '69Z 302 - current header recommendations please?
« Reply #3 on: September 08, 2013, 04:52:24 PM »
Hi Charlie

I have Hooker Super Comps-P/N 2131.  Fit is okay-had to dimple near the p/s box on cyl. #3 tube, and at the pitman arm.  I've seen some posts that state the right side header hit the idler arm. Never had this problem.  Also the left collector flange hangs a little lower than the right.  Just a side note- I put a set of headers and dual exh. on a 1970 z/28 I had while in college.  The power difference was night and day (felt like I put a blower on it).  They may be a headache to install, but are well worth the headache.  Probably a true 35-40 horsepower improvement. 
Good Luck
Harry

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Re: '69Z 302 - current header recommendations please?
« Reply #4 on: September 08, 2013, 06:15:08 PM »
The last headers I purchased for my '69 Z28 (no PS), I had to remove the reverse lockout mechanism, which I didn't like to do, and now I'm still hunting in my shop for the lower rod that I removed at that time.    and those also 'hit' the floorpan at the collector which I didn't care for.

Which available headers for a '69 302 do NOT require removal of the reverse lockout rod?  and fit the best with the other factory equipment?
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Kelley W King

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Re: '69Z 302 - current header recommendations please?
« Reply #5 on: September 11, 2013, 02:56:19 PM »
October issue of Popular Hot Rodding has some interesting header articles. The one describing the temperture difference of Coated versus painted really woke me up. They run much cooler.
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69Z28

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Re: '69Z 302 - current header recommendations please?
« Reply #6 on: September 12, 2013, 08:05:43 PM »
I couldn't say what brand of header I had on my Z when I first bought it, and I still have them hanging on the wall in my garage, but I  purchased a repro lower lock out rod from Rick's in 2001 and it fit with no problems and had pretty good clearance. I'm gonna go out on a limb here and say headers are headers no matter who you buy from and what coating is on it, at least for the street I would think. I don't think the exhaust gases really have any idea what they are going thru. I had so many problems with changing spark plugs and burnt spark plug wire boots I just yanked mine out and said forget this. I kind of like the day 2 look with white headers myself, if I was to change my way of thinking on headers, but I don't think I'll do that anytime soon.

I was looking thru some of my notes from the past few years and at one time on the Team Camaro site some members where going for the Summit 1 5/8", part# SUM-G9001-9 header. I haven't looked at them for a while but I think those are fairly decent and are coated I think and were going for around $210.00 last I looked.  
GaryC

'UNRESTORED' 1969 Cortez Silver Z28 X33 D80

hubleyman

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Re: '69Z 302 - current header recommendations please?
« Reply #7 on: September 13, 2013, 01:20:46 AM »
All the input in this thread is really helpful, and I'm getting close to making a decision.  My engine is done, dynoed and ready to install so it's time to pull the trigger on some headers regardless of the choices.

However, now you guys got me obssessing over those M/T Super Scavengers.  I understand they're hard to find and most likely very expensive if you ever do, but I really like the design of them.  It wouldn't matter if they were originals or reproductions for my usage, but they may just have to stay on the wish list until I locate a decent set someday.

Thanks for all the suggestions!  Charlie

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Re: '69Z 302 - current header recommendations please?
« Reply #8 on: September 13, 2013, 01:35:41 AM »
The headers on my car when I purchased it also had no clearance issues with anything, everything was in place, but after sitting for many years, they were totally rotted, so I bought new ceramic coated headers..   and they DO have clearance issues.. 
I think the original ones were Hedman.  Are those still available? in the same design as original?
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Steve Shauger

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Re: '69Z 302 - current header recommendations please?
« Reply #9 on: September 13, 2013, 05:58:45 PM »
I had my 302 rebuilt and the only modifications are roller rockers, a custom grind cam, headers (hooker comps) and what ever magic the engine builder did and it dynoed @ 419 HP and 372 lb/ft of torque. I know many love the orig 30/30 (long ramps and single pattern grind) but the responsiveness of this engine exceeded my expectation. Plenty of torque with a close ratio and 373's, so drivability is excellent.
I picked flowmaster american thunder exhaust system but installed the 50 series low profile mufflers. I did this because I had the 40 series (on another car) and the resonance was too annoying for me.
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william1

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Re: '69Z 302 - current header recommendations please?
« Reply #10 on: September 20, 2013, 03:16:18 PM »
were not the pipes on the mt scavengers all the same length ?

Kelley W King

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Re: '69Z 302 - current header recommendations please?
« Reply #11 on: September 20, 2013, 03:46:02 PM »
They were but did it in the collector. If you looked in the collector the tubes were ran until all 4 were equal. Someone was reproducing the at one time.
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jdv69z

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Re: '69Z 302 - current header recommendations please?
« Reply #12 on: September 20, 2013, 06:51:42 PM »
Charlie, interesting to see what others recommend, but I have heard good things about Doug Thorley Tri-Y headers, especially regarding underside and engine bay clearances, so will be getting those for when I reassemble my car.

I'm running these and am happy with them. Only thing I didn't like was they sounded like they had back pressure when accelerating normally. The Hooker comps I had on previously did not. Anyway, I add an H pipe to the exhaust, and that eliminated the back pressure sound.
Jimmy V.

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Re: '69Z 302 - current header recommendations please?
« Reply #13 on: April 13, 2014, 06:28:10 PM »
I had my 302 rebuilt and the only modifications are roller rockers, a custom grind cam, headers (hooker comps) and what ever magic the engine builder did and it dynoed @ 419 HP and 372 lb/ft of torque. I know many love the orig 30/30 (long ramps and single pattern grind) but the responsiveness of this engine exceeded my expectation. Plenty of torque with a close ratio and 373's, so drivability is excellent.
I picked flowmaster american thunder exhaust system but installed the 50 series low profile mufflers. I did this because I had the 40 series (on another car) and the resonance was too annoying for me.

Steve, 
1) How about some more info on the roller cam you used?   source? specs?  price?  availability? etc.. 
2) Did the Hooker comps interfere with your rev LO rod?

Gary
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ban617

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Re: '69Z 302 - current header recommendations please?
« Reply #14 on: April 29, 2014, 10:03:03 AM »
 Stahl closed the shop down I believe ....

 

anything