I'm not very familiar with the intricacies of the modern Olds engines, sorry! Are BBO and SBO headers interchangeable? I have a 455, in a custom chassis, in a car it doesn't belong. I'd like headers, so I can modify them to fit, but not sure I want the bigger tubes that BBO headers have. I might have better luck working with the 1 3/4" tubes that SBO usually have. High performance is less an issue that making them fit, and ease of modifying, and buying extra bends.

 

they will bolt up but the overall length of the sbo headers will hang lower on the 455, technically giving you more metal to play with

 

Other way around.

BBO is taller than SBO, so BBO headers are taller (from bottom of the header to the exhaust flange) than SBO headers.

So you can mount BBO headers on an SBO, but they'll hang low, might run into the crossmember.

Hanging SBO headers on a BBO is likely to smash into the floor.

A 1 7/8 tube is just fine. Don't sweat it. The 455 will move plenty of air.

 

your right my bad, need another cup of coffee

 

Hooker makes a 1 3/4" header for the BBO(#3902), and Thornton makes a shorty header

 

Heddman and Sanderson also make a shorty header.

 

Watch out the flanges are not cocked. I got a pair of Hookers recently and one side had a 10-15 degree slope on the flange. I didn't notice until everything was together, bummer. Where else would anyone complain about cocked hooker flanges?

 

Thanks, guys! Not interested in shorties. I'm doing something very unusual, on my car here. I'll have to remember to post the results here, when I get it done.