1963, 383 cheap power upgrades

[73ScampSS]

Hi folks, I am looking to make some power upgrades to my 1963 383 engine.

The previous owner put a Holley 670 street avenger and Mopar dual plane intake, and it still has the stock single exhaust and a midas muffler. The book says it was 10:1 compression, and I've heard they had around 300hp when new.

I read putting a new carb, intake, and exhaust can add upwards of 30hp to these engines, so I want to finish that combo by doing the dual exhaust. There was a set of hooker super comp headers in the trunk, and I was thinking either 2.5 or 3" exhaust out the back.

Its a Dodge Custom 880, 4 door, so its heavy. It has 85,000 miles so probably doesn't need a rebuild; it runs really good, doesn't burn oil or smoke, but I haven't checked compression. It was sitting for 8 years and I just got it running again.

If the dual exhaust doesn't perk it up enough, I would consider swapping cams or some other upgrade, but at this point I haven't decided to keep it or try to sell it later.

What are your thoughts on it? Thanks

 

[Lionized]

Slip a cam in if you're thinking of swapping the carb/intake and adding dual exhaust with headers. 2.5" would work.

 

[mmissile]

2.5 would probably run better. Adding a cam, can be a big job.

 

[AR67GTX]

My first car I owned as a teenager in the 60s was a 64 383 Sport Fury and I raced about everything I could find with it - fairly quick for a stock car at the time. I eventually swapped a 280 cam in it and other than give it a slightly better rumble at idle I didn't find it to do much for performance. It seemed to actually soften performance off the line. My car was fairly quick up to about 40 or 45 and had a killer downshift to first gear at up to 40 mph. Second gear was OK and third gear was a bit of a snooze. The one time I took it to the quarter mile strip I was the only car in my class and they lined me up with a stock 66 Hemi Charger. Surprisingly we hung pretty tight through most of first gear but after than he just started to gradually and steadily pull ahead of me the rest of the way and probably finished 3-5 car lengths ahead (long time ago but best of my probably optimistic memory). My belief - the small valve heads at the time really choked these motors at higher rpm and above about 80 mph.

To answer you question my first change IMO, based on the above memories after the dual exhaust I would look for a set of 67 440 heads which are a bit rare. After that a set of 906 heads from 68 on. Not sure without checking how the combustion chamber volumes compare on the 906 heads. May loose some compression in a straight swap. If you can afford them, a set of Edelbrock heads would be even better. After that, a good intake and headers or magnum exhaust manifolds. Then you could take advantage of a cam swap.

And don't forget the distributor. Most of them wore the bushings out after awhile and couldn't hold steady dwell. If it's been replaced over the years with a remanufactured one, there's no telling how it's set up. Making sure the distributor is in good condition and blueprinting the advance curve is always a good first step.

 

[747mopar]

I'd upgrade the cam to something mild in the rpm range of 1,500-6,000 (going much bigger requires different converter, gearing, etc), I'd stick with a dual plane but maybe an Edelbrock Permormer RPM, install the Hookers, go 2.5 on the pipes and install a 750 Holley or Quick Fuel. I really like the QF and ordering them threw FBO is the best route I've found, cheaper and he'll have it setup for your motor making the intall a lot smoother. Being that heavy I'd probably stick with the vac secondaries especially if it's an automatic.

I've got Hooker Super Comps on my motor and am very happy with the fit, nice header.

 

[eric383]

I would do the headers and 2.5" exhaust first and see how it feels. Also make sure that at wide open throttle the carb is fully open and try advancing your timing a little (just don't let it ping). Any idea what gears you have in the rear end?

 

[Darthomas]

All good advice above.
I put a 68 factory roadrunner cam and heads in my 1966 383 4 barrel, because I wanted deeper breathing without sacrificing too much low rpm torque.
And I advanced the cam 5 degrees to partly compensate for other changes.
Been very happy for 30 years with the results.

 

[rumblefish360]

Hi folks, I am looking to make some power upgrades to my 1963 383 engine.

The previous owner put a Holley 670 street avenger and Mopar dual plane intake, and it still has the stock single exhaust and a midas muffler. The book says it was 10:1 compression, and I've heard they had around 300hp when new.

I read putting a new carb, intake, and exhaust can add upwards of 30hp to these engines, so I want to finish that combo by doing the dual exhaust. There was a set of hooker super comp headers in the trunk, and I was thinking either 2.5 or 3" exhaust out the back.

Its a Dodge Custom 880, 4 door, so its heavy. It has 85,000 miles so probably doesn't need a rebuild; it runs really good, doesn't burn oil or smoke, but I haven't checked compression. It was sitting for 8 years and I just got it running again.

If the dual exhaust doesn't perk it up enough, I would consider swapping cams or some other upgrade, but at this point I haven't decided to keep it or try to sell it later.

What are your thoughts on it? Thanks

My thoughts are a good set of headers and 2-1/2 exhaust will add 30+ hp.

The MP dual plane intake is a aluminum copy of the iron unit which in itself is a good intake. The power gain from swaping to a RPM is not really a cost effective move. But it will add up at the end of the day.

I would also look at a larger carb myself. A Holley 750 would be a good choice IMO.

Moving onto the cam, one with a lift that takes advantage of the heads flow abilities is the first item I would check. Then get the cam in a duration suitable for your driving. It must compliment the tires, axle ratio & torque converter (unless changing these things is an expense your OK with.) As well as the cars weight.
A cam of 218@.050 can still use the stock converter with 3.23 gears though I would not go numerically lower or to much of a larger tire.
A stock head bowl ported works excellent here by the way.

 

[73ScampSS]

Thanks for all the great replies. I have considered putting a cam in- in the future, but I haven't fully decided on keeping this car. I am more of an A-body guy and more into '67-up.

I am stuck with the Holley 670 for now, but I will be tuning it by wideband o2 once I get the exhaust put on. I got a quote for $650 for the exhaust from the headers back, but I may instead get a kit from jegs/summit and weld it myself.

The engine does have electronic ign, I put it on a few years ago, with an orange box, and the timing is at 10* (stock) and I believe 34* total with vac advance. It was supposed to be a performance distributor if I remember correctly.

Unfortunately it has a peg leg 742 case and 2.76 gears, and stock converter, but I have been keeping an eye on the suregrips that come up for sale... Just not sure it would be the best money spent quite yet.

Today the master cyl went out, and the booster is cracked internally, so I am working on getting brakes fixed so I can drive it. Does anyone have experience swapping the booster out with a newer model that's cheaper/available? I am going to post in a brakes thread. thanks

 

[rumblefish360]

Between headers, converter and gears, there the best money spent that show instant results you feel. Cam, carb (carb size is fine by the way.) compression are less and require the best showing when working in concert with the (correct) combo.

If you find some gears, go for it.

IMO, make a move to the Chrome box or other like it. Like a "FBO" box or a revenator.

Header kits / small blocks / my review

I did a Summit and a Jegs kit. The Jegs kit I a small block Duster with the recommended Hooker headers was a very good fit with minimal trimming. Sound was good. Not to bad inside the car at all. Good outside the car.

The Summit kit was mislabeled as fitting the wrong headers (Hooker Super Comps) for my '79 Magnum but I did fiddle with it and fit it in. (The header to use is regular 1 size fits all header.) The pipes had to be cut and rerouted. Easy to do. Very time consuming. Some extra 2-1/2 X 2-1/2 AutoZone pipe connectors are needed for this. There cheap.

Both were very good kits.