Header recommendation?
 

100% dedicated 65 GTO drag car with 68 Pontiac 400 (461) and 68 #16 heads
Car runs 7.58 in the eigth which should put it just a bit under 12.0 I would think.

Car currently has Hedman straight through headers 1.75" primary tubes into 3" collectors (#35010 I think, on car when purchased) with header extensions

Ran the car on a dyno yesterday and first recommendation was to change to a header with a merge collector.

Any thoughts on this advice and/or recommendations?

Thanks
DV

These might be of interest....

https://www.motortrend.com/how-to/cams-carbs/

https://www.speed-talk.com/forum/viewtopic.php?t=59881


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Save your money for some other upgrades

This.

You have a car running 12 seconds flat/high-11s with headers that are not a bad size for your combo.

Spending about a grand for a nicer set with perhaps bigger tubes and a merged collector won’t buy you any huge gains if at all.

If the car picks up maybe a tenth in the quarter would that time and money be worth it?

Thanks guys for your thoughts I really appreciate it. There are likely some other things that might make a better improvement for the $ in the suspension

Figure there are cars with 600 HP running 1 7/8 headers! My RAIV 400 ran faster with 1 3/4 than 2" headers!

I can recall reading where Floyd Hand was running 1-5/8” primary tube headers and running into the mid-11s with a 455 in his ‘66 or ‘67 Le Mans.

A good friend of mine had a 72 GTO, 455 HO. He was a small time local area racer. May have only raced at Cordova, Illinois track 82 and earlier. He moved to Oklahoma in 1982. Never raced the car here, had plans to, though.

Anyhoo
He made connections with other stock racers in his part of the country. Back then cam choices were very strict, not much of a choice. The racers with money to spend started using cams that had extremely fast opening and closing ramps. Some referd to them as "square" lobed cams. I'm not sure if his engine had one of those.

Back to headers>>
My buddies name is/was Richard Allen. He passed in 2018, Parkinsons claimed him. He was a medic In Viet Nam for one year. I would fearfully guess that any Viet Nam vets still might have Parkinsons. 3 men on the small street in Muscatine Iowa, where he moved back to in 2017 have it...

Headers. Richard knew Rock Running, He had a car similar to Richards. He had a set of 1-5/8 inch tube HO headers he wasn't using. They were Headers by Ed. He and Rock swapped some parts. Richard said those headers were hell to install. I know, we (I). put new header gaskets on it, to prep it to sell. He said they DID help. he said he picked up 1-2 tenths.
All this may be meaningless. Nobody runs a cam anwheree near a square lobe 068 in any of their street engines. Just throwing it out.
Thanks for reading!!!
Jeff