66 Coronet 4 bbl upgrade

[mtbase]

I've completed my 66 Coronet 500 restoration. Mine was,and still is, the original factory 361.
This engine setup only came with a 2bbl carb, my goal was to get it to work as it would have rolled off the assembly line. The 2bbl was difficult to rebuild, as it wasn't very popular...and I know why Car and Driver magazine called it a "boat anchor". For a big block...leaves something to be desired. The engine is "factory", bored and sleeved to be a 361ci, the only change I made was a somewhat more aggressive cam in anticipation of a 4bbl. I'm asking for advise on selecting a more modern 4bbl and manifold that will fit the original configuration, as I will not be cutting a hole in my hood. I'm not looking to get into street races, but I do feel that it should be more lively that the 273 in my Barracuda

 

[66 Sat]

I'd look at the Edelbrock Performer with a 600 vac sec carb. It'll be a whole lot lighter on the front end too.

 

[Big Bad Dad]

I have a 361 in my 64 Fury. I put a factory 4 bbl intake and carter afb from a 383 Chrysler on it a few years ago, while trying to keep it stock looking. The factory 2 bbl air cleaner will work with an afb. But a later avs or an Edelbrock has a larger air horn.

 

[Don Frelier]

I would recommend the early 500 cfm AFB. Easy to tune and the small primary will make it very responsive. Big bad dad makes a good point about the air horn size. But you could make a new air cleaner base pretty easily

 

[Coronutcase]

You might want to add a one inch spacer while you're replacing you carb and manifold as well. yor hood should still be able to close. I would also go with a manual choke on the carb, I just prefer them over electric.

A set of TTI headers will help too, but not sure what your budget is and how far you want to go.

 

[66Satellite47]

An old EDE DP4B is a really good manifold for that motor. If you can find one. The 600 to 730 Holley will work well The old 3310 was a great carb that didn't seem to care what the motor combination was, it just worked. Adding headers will make the motor come alive.

 

[mtbase]

Budget is not the concern. I've put way more money into it than I can get back...its my baby. While I understand the benefit, headers will never happen, and the hood insulation touches the air cleaner on closing now, I don't believe there's another inch there. The look of "big bad dad's" engine compartment, is what I want to maintain. I've heard that the Thermo Quads were good and were an original for big blocks of that year, but Edelbrock's or Holley's have evolved and fuel economy is better, choke's is vastly improved. I'm aware that the air horn is larger on these, I have another air cleaner base that I could sacrifice ( why could't they have kept that the same??). Thank you all for your experience and advise.

Will a aluminum manifold really make that much of a difference, over a "stock" in the end?

 

[66Satellite47]

Hard to imagine your hood clearance is that close, but what ever. A HP aluminum manifold is likely to be 1" taller. Thermo quads work if you figure them out.

 

[Don Frelier]

Have you done anything with the ignition?
A different cam may need a little more initial timing and quicker mechanical advance ( lighter springs).
Those ran pretty well with a big 2 barrel.

A slight correction, the thermoquad was not in production in 66.

 

[Slap Stick]

I've heard that the Thermo Quads were good and were an original for big blocks of that year,

Nope. Chrysler started using them in 71.

I vote for a 600 Holley. Ez to work on.

 

[Don Frelier]

If you like the stock look. Consider 68-69 hp exhaust manifolds with an h-pipe and hemi mufflers. it will sound great and breathe well.

 

[mtbase]

I have thought about an electronic ignition. Thoughts on that are appreciated as well

 

[66 Sat]

Will a aluminum manifold really make that much of a difference, over a "stock" in the end?

If you can get a stock 4 barrel manifold then maybe not that much other than 20 kgs sitting high over the front wheels. If you're changing from a cast iron 2 barrel manifold, then with the carb (and cam you already have) it should transform the motor. Years ago I had a lowly 318 Barracuda. I installed an Edelbrock Performer manifold and cam, 4 barrel Holley, headers and a dual exhaust and it was literally like a new motor had been installed. When I added electronic ignition (it was a Mopar Orange box) the change in the throttle response was huge, however when I added electronic ignition to a later 351 Cleveland the change wasn't really noticeable which was disappointing. With all these engines in a low state of tune, it's the combination of many changes, some small & some large, that can make a huge difference overall. Or there could be an existing problem that's holding the engine back. On the Barracuda the exhaust manifold heat valve was rusted nearly closed, which I only noticed when we took the manifolds off. When I changed to headers it opened up the breathing tremendously. Obviously work to the heads will make a big difference but small easy changes like a clutch fan etc will all help.

 

[66Satellite47]

Dumb add but pocket porting any BB Mopar head results in major performance increase. Grinding below the valve seat makes HP.

 

[mtbase]

I was under the impression that Edelbrock was the new "hot" carb on the block.

Would you port polish a intake manifold?? Sorry if it's a dumb question

 

[66Satellite47]

The EDE carbs are the same as the old Carter carbs. Decide what you like for your tunablity. I found Holley's easier to work with. But I had a Carter AFB that worked great for several years. Port the manifold to match your heads.