My Clifford shorties are shot.I am going to make my own new set and wondering If i should stick with 1 1/2 primaries or go with 1 5/8 longer primaries? Does anyone have personal back to back comparison?Trying to read and gather as much info before I build a set that slows the car down.ANY guidence appreciated.Mark

You probably should determine the cross section size of your exhaust port. You might find that it may already be larger than a 1-1/2" tube if its ported very much, and using that small of a primary tube may actually be choking it. The difference between an 1-1/2" and 1-5/8" is really very slight and probably more ideal for a higher HP engine or one that uses a power adder. I would prefer to build a step design with an 1-5/8" primary and then merge into the 1-1/2".

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There's no such thing as too much cam....only not enough engine!

According to my numbers using a Dave Vizard article on pipe sizing, I think you should go up to 1 5/8" primaries. Most Slants will not need it, but you are up there in power and should benefit from a larger primary. Can't find the article at the moment, but this is a clear memory that if I were to do new headers I would go up to 1 5/8" for 250+ HP Slant.

Best,

Lou

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Home of Slant6-powered fun machines since 1988

Mark, Build me a set while you are at it!


Greg

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http://www.youtube.com/hyperpack

Oh, also I would suggest shooting for about 30-32" primary length. Cameron Tilley showed me a room with more than a dozen different Slant headers hanging on the walls back in 2005, and said his best dyno pulls were with primaries in this range. Not saying it is absolutely necessary, but food for thought...

Yeaaahhh, make me a set too...

Lou

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Home of Slant6-powered fun machines since 1988

Where is that gorgeous set of stainless, stepped headers from "the Blue Car"?

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Yeah....Im the one who destroyed this rare, vintage automobile.....

By Blue car do you mean Seynmour's Valiant Drag racer or Dave Muller's Wagon?


Ryan Covalt is now the Owner of the Seymour Valiant.

I would think he still has them.


Greg

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http://www.youtube.com/hyperpack

And just to bee clear I am talking outside dia.Clifford shorties that I have are 1 1/2 outside dia.The 1 5/8 primaries that I think I want are 1 1/2 inside dia.My flanges with little stubs are a little bigger than the ports in my heads and are 1 5/8 outside dia.I will do alot more research but my feeling is that Lou is correct on the 30 inch primary length.Y pipe around 15 inches after that.My headers will bee one off and just might bee fender well because of engine set back and rear steer rack and pinion.Mark

I meant Mike Jeffries "Blue Car" I think it was a 68 Valiant. The headers were shiny art......

But ....mebbe any blue car would do....

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Yeah....Im the one who destroyed this rare, vintage automobile.....

(Mikes car was a 10 second nitrous car)

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Don't think they were stainless, the shiny was Jet Hot coating.

I had headers built for the Daytona. They are 1-3/4 to 1-5/8 steps because Jeff didn't have enough of either for the whole set. Hedid make the primaries as close to 32" as he could.

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Official Cookie and Mater Tormentor.

I haven't seen the buzzin half duzen car for the better part of 10 years. . I bet it's in a building in the middle of a field in Nebraska Greg

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http://www.youtube.com/hyperpack

The blue car is actually for sale. Mike is having way too much fun with the stocker.

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Official Cookie and Mater Tormentor.

Front three headers built,1 5/8 dia 34 inches long.They are fenderwell headers.Alot more work and time than I thought,and the rear three are going to bee even harder.Got the front three within a 1/2 inch of each other.Will try to post pics when they are ALL done.Mark

Blue car? Think we have a few!





Building headers is always an adventure! As for tube size I have no evidence to give input on.

Will