Looking to purchase headers for my project. The engine is a 493 CID with Edelbrock RPM heads, a Crower roller with around .600 lift and a FAST fuel injection setup and I think it will make in the 550HP range. Car will be mostly street driven and have a 3" exhaust system but will also be taken for some passes at the local strip. I'm trying to decide whether to go with 1 7/8" tubes and 3" collectors or 2" tubes with 3 1/2" collectors. The 1 7/8" tubes are an easier fit especially with power steering, but I don't want to choke up on the exhaust either. Thoughts?

You are saying street car...the smaller 1 7/8 will help you build low end torque plus are much easier to install. 2 inch if you want max hp. I say especially a heavy b body with... say 3.23 or 3.55 gears, go with the smaller tubes.

For what your doing 1 7/8 are fine.

Roller cam it and wing it past 7G's
then the 2 inch will be needed!

I run 1-7/8th on a stroker 440(500ci).
Does 12:00@118+ at 4000 lbs & 2:75 gears.
Does 17 mpg Imperial (about 19 US).
Steve Dulcich who does engines in Mopar Muscle Mag, has said he has made 670 HP on 1"7/8th headers.

1 7/8 would be best.

Thanks.... 1 7/8" it is then.