Aren't there two Dougs? Doug Thorley Headers and Dougs. Heard years ago he got a divorce so there were/are two companies.

Yes

The only problem with the Doug's headers for your build is that they're only available in a 2" primary. That is too big for a mild 440. I saw this first hand when we dyno'd my old 446 and the 2in headers cost 20ftlbs of torque across the entire test range vs the 17/8's. Horsepower remained the same for both sets of headers.

This was on a street/strip pump gas 446 making 535hp/540tq.....probably close to what the OP's engine will be making. The conclusion was obvious ; the larger tube cost some low end grunt.

At the time I had purchased a set of 2in TTI's but knew that I would be going stroker in the future but just wanted to see a fact based comparison between both sizes in the name of information/data gathering.

My 2in TTI's were ordered "bare" and I had them ceramic coated locally and they've held up fine for several years. Some dulling on the primary tubes near the port exit but zero rust issues.

I would stongly consider going with the 17/8 primary TTI's and have them coated locally so if there are any warranty issues with the coating it won't be a big hassle.


Charger's are heavy beasts....I know because mine weighs 4150 race ready. No way would I give up 20 ftlbs of torque that I didn't have to. This is basicly free power for just making the right choice with a header primary size...



Ron

A stock stroke 440 based build with a dual plane manifold and a cam that's 236/242 @.050 isn't going to have a powerband high enough to be able to exploit a 2" header....... IMO.

A stock stroke 440 based build with a dual plane manifold and a cam that's 236/242 @.050 isn't going to have a powerband high enough to be able to exploit a 2" header....... IMO.

Good info.....Dwayne would know because he built my 446 and conducted all of the dyno testing noted above.

70Charger...The cam in my 446 was also quite a bit bigger (duration) than the 236* cam that will be used in your build. Mine also had a low rise single plane (Street Dominator) which tends to pull better up top vs a dual plane RPM...at least it did on my motor.

All that being said....the best choice based on hard data would be the 17/8. Just do it and rest easy.



Ron

Ron's 446 was subjected to over 90 dyno pulls, and we tested 3 sets of headers, 4 or 5 intake manifolds, several carbs, spacers, timing, and two camshafts.

Sure, the "biggest" of everything made the most hp....... But the low end TQ was waaay down compared to some of the more common street set-ups we tried.

Ron's 446 was subjected to over 90 dyno pulls, and we tested 3 sets of headers, 4 or 5 intake manifolds, several carbs, spacers, timing, and two camshafts.

Sure, the "biggest" of everything made the most hp....... But the low end TQ was waaay down compared to some of the more common street set-ups we tried.

Those are some good numbers for sure. The pistons I'm using are Racetec and they weigh 670 grams attached to ly rods and ARP rod bolts, steel crank turned and I did go hydraulic roller cam as recommended here for the 1.6 Rockers because I wanted to stay hydraulic. I hope this build works out good for me. I'm still undecided on which and what size Carb. The motor will build what it will build in hp. I just want a good street car. Figured it would have 550+ hp but if it don't that's fine to.

Those pistons are significantly lighter than mine....should spin up real nice. With that cam it will be done at 6000 so there's no point in over revving it past that point, especially with the hyd lifters which don't like high rpm anyway.

The TF240's are better than a stage1 RPM head, no doubt. The choke point is going to be the RPM intake manifold. Overall it's a well matched combo with the dual plane and that cam....they will play well together. I'd look at a quickfuel 850 DP'er to top it off.

That is a nice cam....a friend ran that same grind in a similarly built 440 in his 71 roadrunner. Nice lope at idle and strong throttle response. Fried the tires at will. He was running 3.55 gears and a 3k stall.



Ron