Hi all, I have what appears to be Hooker Headers. The headers dont really fit right and are getting old. Think they came out of another type car and they just made a fit of them (They are the long type). Anyways besides that. I've got a 67 327/275 HP, Holly 650 Spreadbore, MSD 6AL, Camel 2.02 Heads, Mild Cam, Muncie, Alum driveshaft, 3:73 10 Bolt now, in my 68 RS. Does real well in mid to high end, still needs work on the low end. The problem is it revs real high, its a torquey engine. May even have a 283 crank in it, I'm not sure, but its a high rever. But as soon as I release the clutch I have a power drop off. I am running a bit rich, but barely noticeable. Will changing to shorty headers help? Cam and head and stall convert work is down the line probably this Winter. graemlins/beers.gif

I've got:
327
1405 edelbrock carb
Edelbrock performer intake
461 heads
3 speed manual
positrac rear end

Put on Ceramic coated Dynomax Headers last weekend. Fit and form were perfect. Had to remove the Z bar to get the driver's side header on. Picked them up for $269.00 - you might be able to find them cheaper though.

I got the dynomax ceramic coateds as well. Bought them through Summit Racing for about $210. I did have to dimple one of the tubes for plug clearance, but other than that the fit was ok. A little close to the PS box, but haven't had problems.

I ALSO have the dynomax headers and they do fit in easily. The passenger header can slide in from above without the car on a jack, and the driver's side goes in easily from underneath the car...with the oil dipstick removed. My manual steering box was really close though, and I just took a couple thousanths off of the box with a file so that it doesn't rub. My steering box is aftermarket though.

Any noticeable low end performance gain on these short strokers? I mean the 302/307/327 were never known for the "off the line" power, unless seriously cam'd and geared and everything else.

Am I wrong? So these shorty type headers can move the power curve lower into the RPM's?

If I remember right diameter rocks the power curve either up or down at the torque peak whereas length rocks it up and down the rpm range...

In other words, small, long headers promote great low end torque whereas bigger, shorter headers promote more top end power!! That is if the cam is a match!!!

But it's been a while since I thought of this so may be wrong.

There are programs that can help figure this b/c David Pozzi e-mailed me one..

BTW, you might do a search for a set of 1.5" primary tube diameter, four tube, long headers and check if they don't help promote better low to mid torque production...

pdq67

Long tube 1-5/8" headers would be my pick. You can get them with thick wall tubing too (Hooker Comps - not supercomps) which reduces the diameter further.

Headers won't totally cure your lack of low end though - that's a stroke/cubic inch issue.

Good luck.

Yes small tube long headers. Scavenging collectors welded on OR an X pipe. I'd go with a 3"X3" X or 3"X2.5" Xpipe.

But first. Holley carb? Not real familair with spread bore charaterisitcs, but if its a DP, think you'd be better off with a square bore 650. Nevertheless, check float level, be sure to have a PV rated 1-2" below idle vacuum in front. Then play with your pump cams and squirters to optimize shot. Sounds like you need more shot.

Check timing to ensure you have a decent curve in there. Say, roughly, 18-20 degrees all in by 3000.

If you have an M21, it's hurting you. Swap to an M20, OR a ST10 with a 2,88 1st gear.

Depending on cam, looser lash setting might help. Say, 1/4-3/8 turn down on a hydraulic.

Lastly, if you want to go this far, check your cam timing. After you check TDC with a piston stop, roll the motor over by hand with the drivers' side valve cover off. As you come up on #6 TDC, watch the action of the #1 valves. You'll see the ex valve closing and the IN valve opening as you near #6. AT 6 TDC if the IN valve is closer to the head ( it passes the EX valve on the way down), you;re OK, the cam is in advanced. If they are level, the cam is "straight up", but if the EX valve is still closer to the head surface ( I measured from retainer to head surface), the cam is in retarded. If so, I would pop the cover, drill out the pin bore and put a bushing in to advance the cam some.

These are the steps I'd follow to ensure the combo is setup right before I tore it down.

Originally posted by Baby68RS:
Hi all, I have what appears to be Hooker Headers. The headers dont really fit right and are getting old. Think they came out of another type car and they just made a fit of them (They are the long type). Anyways besides that. I've got a 67 327/275 HP, Holly 650 Spreadbore, MSD 6AL, Camel 2.02 Heads, Mild Cam, Muncie, Alum driveshaft, 3:73 10 Bolt now, in my 68 RS. Does real well in mid to high end, still needs work on the low end. The problem is it revs real high, its a torquey engine. May even have a 283 crank in it, I'm not sure, but its a high rever. But as soon as I release the clutch I have a power drop off. I am running a bit rich, but barely noticeable. Will changing to shorty headers help? Cam and head and stall convert work is down the line probably this Winter. graemlins/beers.gif You may want to consider the Doug Thorley tri-Y headers. Good fit too.

Bob.

You have to think small when you are working with a 327. Think long if it's a street car.
We run 1-5/8" x 40" primaries with a 2-1/2" merge collector into a 2-1/2" Dr. Gas XCO on our 331" Nova road racer. Very good mid-range torque, it's a great hill climber.
We also had a 331" Vette with 1-5/8" x 34" primaries, a 2-1/2" merge collector, 2-1/2" Dr. Gas XCO with Dynomax Super Turbos. 380 hp to the rear wheels at 6000 rpm, another great road car.
You can go to www.headerdesign.com (http://www.headerdesign.com) and get a good idea what would work well with your car.

Thorley tri-y's........