5.9L Magnum questions

Here a manifold header shootout on a stock 4bbl magnum, there's another out there somewhere that has magnums and there basically on par with 340 ones, they found the best combination to be one 340 and one magnum manifold, I forget which ones but was only better by a hp or two.

As for 273 manifolds who knows probably slightly less than 318's, only dyno test I've seen was a set of tti headers gained 10.8 hp on a stock 273 Commando.


Legend318:Stock '69 A-Body exhaust manifolds with 24-inch extensions360:Stock '77 360 iron log-style exhaust manifolds with 24-inch extensions340:Stock '70 340hp exhaust manifolds with 24-inch extensionsSHT:Hedman 151/48-inch-tube shorty headers with 24-inch extensions 1 58: Hooker Competition 1 58-inch ceramic-coated header tti: Tube Technologies Inc. 1 58x1 34-inch chrome step header 1 34: Hooker Super Competition 1 34-inch header; bare, uncoated

https://www.motortrend.com/articles/mopp-0307-installing-exhaust-headers-into-300hp-crate-engine/