header tube size

[Wade_Owens]

Originally Posted by chassis1

for the combination you run, there are very interesting ways that are not simple to make the small engines move more air then ever thought. Believe it or not, it is done with the 4 into 1 and not the tri-y because of the cfm of the smaller heads......sometimes you can speed the air up too fast and the smaller engines do not like it.....

Chassis1

[Jeff Teuton]

Here is what we got; 360 motor wedge 1 5/8 to 1 3/4 to 1 7/8 with merge collector, 370 motor hemi; same size one runs to 7k, the other past 8k, the 370 liked a 1 3/4 to 1 7/8 about 5 better one made 540, one made 660.

[Ed Wright]

Strangely, mine doesn't appear to like step headers. Been running them (1 3/4" to 1 7/8") since last year, but I have never even had the thing on a dyno until recently. Bought them on the recomendation of someone I really respect. The step headers only appear to help down around 5000 RPM. Past that straight 1 7/8" picked it up everywhere. If I were foot braking they might be worth more. Wonder what I'm doing wrong, that it doesn't appear to like them, when everybody else runs them?

Thinking about trying a set of 2" primaries? My old, original-1975-rules-292" C/SM Camaro loved 2" headers. But, it was a stick car leaving over 8000. This is a 358" LT1 trans brake car, the converter hits about 6000.

[chassis1]

1.750 is way too big for the lt1 first step.......measure the ports one of the heads, I think they are more D shaped and barely over an 1.500.....

and remember, just because it is a step header does not mean the steps are correct......

Chassis1

[Ed Wright]

Originally Posted by chassis1

1.750 is way too big for the lt1 first step.......measure the ports one of the heads, I think they are more D shaped and barely over an 1.500.....

and remember, just because it is a step header does not mean the steps are correct......

Chassis1

The 1 7/8" are even bigger, yet made more power 5500 + up.