I'm doing a rebuild on a '66 Chrysler Newport. It's a 383 2-bbl. The engine is all-original (points distributor, Stromberg WWC carb etc.)

I want to tow a 4000-lb trailer with this car, so for the rebuild I want to put a slightly bigger cam in it, but still something with good idle. Someone mentioned to me that Chrysler had a factory "magnum" cam that gave more low-end torque but was still a smooth-idle cam.

I've looked all over for such a cam, or for specs for it, and haven't found anything. Does anyone know how I can get specs for a "magnum" cam, or who might be building something similar these days?

 

Probably has a 2.76 or 2.91 rear. Best thing to do is put a 3.23 rear gear in it !!! Maybe a 4bbl intake and a 4bbl cam...

 

Also check on getting a type III hitch if you do not have one

 

Towing a 4000# trailer with a 50 year old unibody car...you, sir, are bold. Yes, the .454 Magnum 4bbl cam should do nicely. And might I suggest some subframe connectors and torque boxes.

 

Can I use the .454 cam with my 2bbl setup? I'm not looking to upgrade the carb/intake at this point. If not, is there a similar cam for the 2bbl setup?

Btw, I had a custom category 3 hitch made (according to original specs for the car, given in the owners manual) that attaches to 4 points on the frame - 2 at the bumper, and 2 points about 3 feet back, under the trunk, to the frame rails. The hitch is an I-shape and made of 2-inch thick square steel pipe. I'm thinking this should stabilize the frame for the load? But point taken about the unibody.

 

Another friend of mine just bought a 66 383, and I was looking it up in my 68 shop manual. Unless something changed between 66 and 68, the 2bbl and 4bbl cam were the same, 0.425 intake lift (about 0.450 exhaust?) and 256/260 i/e total duration, and 30 overlap. If you are interested in low end torque, this cam will probably do better than the 0.454 below 2000 rpm, possibly below 2500 rpm. But I would still swap the cam if I were you, because the torque loss with the bigger cam will not be that great, and the car will be more fun to drive.


The replacement of the 2bbl however to 4bbl will give you a lot more benefits, both in fuel economy and power. The 2bbl setup is really a silly designed, meant for reduced initial cost. The 4bbl carburetor will give you better fuel economy (smaller primaries), better response, and better full throttle acceleration. It is also far less work than replacing a cam.


Before you change your rear end (if indeed it is 2.76), drive the car first towing. If you can live with that, I would leave the gear in there.


By the way, it is critical that you install an oversize transmission cooler, especially with the 2.76 gears.

 

I had a trailer hitch on my 68 newport when I bought the car. I towed a 70 newport on a trailer with it.

In my opinion doing a cam swap on the factory 2 bbl is not worth the time or money you will spend at all. Intake and carb were the first thing I threw in the garbage when I bought my 68 and without these supporting mods I would assume you will not see the gains with the cam that you are looking for.

Love the thought of this build though! Keep up the good work!

 

not safe to tow 4000 lbs with it

 

Demetri - according to my 66 manual, the intake lift on the 2bbl is only .392, exhaust was .390. This is compared to .425 and .435 for the 4bbl (for both 383 and 440 cid engines) for 1966. The valve timing is also a little different.

Based on this feedback maybe I'll price out the 4bbl upgrade. Just a carb and intake, right? Then use the bigger (.425) cam and see what I get.

I did add a deep (4 extra quarts) transmission pan, plus a trans cooler. Also have a temp gauge on the pan to keep an eye on the temp, although I'm not planning to haul this thing up a mountain.

Moparted - I'm pulling a trailer with a brake controller and 4 x 12" electric drum brakes (on two axles.) Also of course using a weight-distributing hitch, custom-made according to Chrysler's plans in the owners manual. Does this change your opinion on safety? I'm definitely interested in keeping this safe. So far it seems to tow easily (it's an old Airstream) but I have only pulled it in eastern carolina, which is a very flat area - no hills. I have thought of converting my front brakes to disc instead of drum, but I'd rather keep the drum brakes if possible - they're one of the quirky things I like about this car. The original owner's manual gives the tow capacity for the car (with their hitch installed) at 5500 pounds. On the other hand, the car is almost 50 years old.

 

If you go through the trouble of replacing the cam, may be you should go with something even bigger. May be go with the HP size cam (.450 intake lift). That would need a dual exhaust system as well. All well worth it, especially if you have a 3.23 and/or you like to enjoy the performance of the big block every now and then. Since you are paying the price of the poor fuel economy of the big engine, you may as well enjoy the potential benefits.

 

I'm already in for the rebuild -- have a couple of cylinders that need to be bored, etc. The engine is already in pieces at the shop. So I'm definitely getting a new cam.

I have a dual exhaust on it - put that on last year. I'll take a look at .45 intake lift as you suggest. I'm looking at comp cams, if you have a specific cam or vendor that you recommend, I'll take a look at that too.

Thanks for all the feedback, this has been helpful.