what size headers should i use?

[Tom Salvo]

I have a 496 cubic inch big block chevy and wanted to know what size headers to order. I was deciding between the 2 1/8 or the 2 1/4.

[Brian C]

Tom, go with 1 5/8" primaries. You'll have a whole lot more oil pan and starter room



I'm such a dick!

[Randy H]

Need some specs on the engine, cam, compression, heads, bore, stroke.
Do you have any HP and torque numbers?

Randy

[Tom Salvo]

 4.310 bore 4.250 stroke 355cc pro 1 heads 286 294 duration .050 112 lobe seperation 14.1 comp turning it 7500. 850 horse 720 ft lbs. this was with a 2 inch header.

[10secBu]

A 355cc head on a 496? 

That's a big head for that size engine.

What weight car? How much stall?

Myself, I'd say 2", maybe 2 1/8" max, but 2 1/4" is too large IMO.

What kind of ET/mph does it run now?

[Randy H]

I would also say 2.125 max if it made peak power at 7200 or below.

Randy

[Tom Salvo]

I ran it last year and had all kind of problems best run was a 9.52 at 144. 3150 pound car with 5800 stall. now im rebuilding it and puting it in a stick shift car that will weight about the same maybe 3100 lbs.

[Tom Salvo]

I know its a big head for that engine size. With the horible rod ratio I was trying to rpm the engine a little more so thats the reason for the big head.

[Richard Maitre]

I would definately build a step header starting at the smallest of the choices and work your way up.

Rich