I'm looking at a set of headers for the Imp. The factory exhaust manifolds are not compatible with Edelbrock heads so a change is required.

Keep in mind that I'm building an ultra heavy, quiet, and comfortable car for cross country road trips. The engine combo on paper (okay, my old dyno software) should be pushing 450+ torque from 2000 to 5200 rpm and tickle 500 lb/ft from 3500 to 4500. Power should be 400+ from 4500 to 6000, peaking around 440 between 5000 and 5500. I'm really doubting the intake will pull those higher rpm numbers but the fat mid-range looks tasty.
Saddle that engine to a drivetrain and power at the ground will be significantly lower.

The headers I'm looking at are:
1) Hedman shorties
2) TTi shorties
3) Schumacher Tri-Y
4) TTi full length 1-3/4

The requirements:
1) Must fit angle plug Eddy heads in a C body.
2) Quality stuff that won't leak.
3) No ground clearance issues.
4) Ease of servicing plugs and starter.

The car:
5300 lb luxo-barge highway cruiser
Power steering
Power brakes
Column shifter
3.23 gears
29" tire
Stock converter
727 (46RH swap planned)

The combo:
440 std bore
10.2:1 compression
Edelbrock Performer 88cc heads
Comp 261/.463 cam
106 center line
110 separation
CH4B intake (low hood clearance)
Eddy carb (to be replaced by FiTech)


Which set of headers would best fit the bill? I was thinking about the Hedman shorties for an easy way out but the TTi shorties and Tri-Ys are looking pretty good. Sadly, I do not have any experience with any of these headers.

I only have one data point for you, but the TTis I installed on my Road Runner with a Hemi fit perfectly. No power steering, but it is a 4 speed car. Only issue I had was having to use aftermarket oil dipstick tube. If I had been smart, I would have bent up a new tube and used stock dipstick. I am also using a mini starter.

You'll need to confirm that C body headers will fit an Imperial.

The front subframe on an Imperial is about 3 inches longer than the subframe on a C body.

I have the shorty hedmans on my 383 in a charger. Hopefully you'll have more room than I will with a 440. Apparently they are a ding fest to make work with the 440. The forward most tube is the problem, the angle will hit the shock tower. Some complaints on Summit Racing about it, I don't have the real world experience, yet.

The wheelbase is 2 inches longer. That puts the engine somewhat farther away form the suspension than a C body. The torsion bar anchor crossmember is in the same place.

Overall, the car is about 5 inches longer than a New Yorker but is essentially the same from the firewall back.

My vote is for the full-length TTI headers. I had to buy TTIs back when I installed Indy SR heads and they were the only ones that made headers that would fit my application. The price made cringe, but I didn't have a choice. They fit like a glove. The quality is great, and I've yet to hear anyone complain about TTI. It's been about 10 years or so since I ordered my headers, but don't they offer a Moparts-member discount? (The shruggy emoji is for real - I don't remember if they offer a discount or not.)

Feets, can the HP manifolds from 69-70 B&E bodies fit the IMP engine bay? I ask , because I have a rb 493 on the stand with E-heads and these manifolds clear the angle plug heads just fine.

When I had my 72 Imperial, I was planning on putting headers and dual exhaust on it. But nobody could confirm to me that C body headers would work. I've since sold the Imperial to concentrate my automotive efforts on my Chargers. (Only so much hobby time and money to go around.) I'm interested to see how this works out for you...I might just wind up with another Imperial some day.

I think the only reason the stock stuff won't work is because of the angled plugs? TTI has been very, very good to me on about 4 different cars I had the pleasure of working on. None were Imperials though...

I think there's an issue with the driver's side exit. The passenger side works fine.

I'm hoping that headers will open up a bit more torque for me.

Will the #7 and #8 plugs clear on the Schumacher headers? From the photos it looks like it would be close. Website makes no mention of Edelbrock heads.

I did some searches and it looks like they'll fit. There can't be much room.

I liked the hedman shorties on my 400ci '72 c body for the first couple years, but they are thinner material (If I remember correctly 18 gauge), I drove the car year round here in MI at the time, and they rusted out sooner than I hoped.

I now have a 440 in the car with regular straight plug heads, and HP manifolds.

Of those choices, I like the tti full length.

I have a brother with a 440 Duster.An honest 425hp car- Iron 906 heads. He went with the Schumachers. In his 74 Duster they simply installed. No lifting removing dinging clearancing etc. Heavy thick steel tubing and flanges. Very install and plug change friendly. But not optimal for highest power production.

Oops!

Robert

Back in the day, the 4-2-1 was known as the torquier of the two designs of long tube headers. The 4 into 1 was known for making more peak hp.
The 4-2-1 sometimes fit a little better because they have fewer tubes and take up less space in the congested area.

For these reason I'm suggesting the Schumacher.

Dyno testing shows that headers increase the torque curve below the torque peak. Shorty headers don't do much more than HP manifolds, if any.

R.

TTI's are well made and if you tell them you have Ed heads at time of order they will make any adjustments needed for plug clearance. I think long tubes would work best... if they fit. Worth asking TTI IMO to get their advice.

To control heat while cruising, ceramic coating inside and out for the long tubes.

If fit is no good or not sure, then the shorties. For what little you would lose with shorties they may make sense so you do not have to worry about fit. Also possibly less heat.