Shorty Headers vs. Hi-PO Manifolds

IS there much of an increase in performance with a pair of shorty headers (Headman) vs. a set of Hi-Po Exhaust Manifolds. The car is a 383 with 484 Cam, 3.91 gears, 906 Heads, planning for 2.5" Exhaust. It is a C-Body car

The Hedman shortys aren't tuned length, so that limits their benefit theoretically.

I don't have hard evidence/data, but after I put shortys on my C-body (it had standard logs) the performance increase was impressive, and I don't imagine HP manifolds would've made as big an improvement.

Depending on your year of C, the HPs make a sharp turn at hte steering column (69-71 cars), so keep that in mind whilst trying to decide.

Either way, those shortys just look like they would flow well. They'll come with 2 1/4" collector hookups, though () so plan on something better. I welded 2 1/2" pipe right to the mating flange and bolted them together. No problems, several years later.

IIRC there was a Mopar magazine that did a dyne comparison several years ago.

Thanks for the response, the car is a 65 Fury, do you know if there is any major issues with clearance. I am planning to use the Mini-Starter.

Tough to say. My car is a 68 and 440. I have a 65 Fury 383, shortys are in the gameplan but that's way on the backburner.

Good plan on the ministarter - 'cuz it's mandatory.

I've heard there is a little grinding clearance required to put these headers on a B-engine. A boss or something on the block needs a little finessing, but it's reportedly minor.

You'll have to watch the clamshell cover and rubber steering column coupler - my 68 doesn't have those. Ironically that's the same thing I was referring to on the 69-71 cars regarding the sharp HP manifold outlet. As HP manifolds didn't come out until 67, I can't say how it would fall together on a 65. That coupler was used in various applications in 65-66 and then some later Cs (i've never figured out the whole pattern). If you go HPs you'll probably want to use a 67 B-body-style manifold that exits at the rear, instead of between #5 and #7 like a later C.

The 65 C has a 1-year motormount on the driverside, I've never been able to determine if the PS gearbox is in a different spot also. It always seems to look like it's a little different, but I've never confirmed.

Here are 2 threads I did on the Drydock, they may help (lotsa pics):
http://www.cbodydrydock.com/forum_viewtopic.php?6.22000
http://www.cbodydrydock.com/forum_viewtopic.php?6.22001

And here's probably the answer to your first question:
http://moparmuscle.automotive.com/124449...m-manifold.html

Go here and then click on "B/RB Under-Chassis Headers" on the left of your screen. These might work for you. I run these headers on my 383 in my '65 Coronet with a mini starter. Didn't have to modify anything. They are a nice fit. They are manufactured by TTI, only sold by Schumacher.

Thanks for all of the replies, I appreciate it. Ill check on those headers too, the 65 Fury is certainly an odd ball.