[storm9c1]

What kind of manifolds are on there now? IMO, 2-1/2" ramhorns versus headers are splitting hairs on anything less than 350 hp and spends most time under 4500 RPMs. I'm running truck ramhorns on a 383 and like it better than headers. I get excellent low-end torque with them which is what I want...and I imagine with your specs, that's what you want too.

Other types of manifolds (logs, 70s and 80s smog stuff, etc) are a different story. I won't ever recommend those.

If I want manifolds, my goto is ramhorns -- either the angled dump truck ones or "Corvette" 2-1/2" center dumps (preferred) if they fit. I've also been known to use 94-96 LT1 manifolds, which also flow very well, but need port matched for other SBC applications. However, the driver's side ones are no longer available new or aftermarket, so that ended that trick. For higher dollar, higher performance applications, definitely a good Thorley (Tri-Y is good for tight clearance) or Sanderson. There are other high-end brands available like Kooks, etc., some target modern cars and restomods, just never had any personal experience with those, so can't recommend. The low dollar headers aren't worth the hassle IMO.