Go with it. I think it is a good place to start. Don't try to dump the headers back into a single exhaust. A simple 2-2 1/4" dual system with an H pipe usually picks up some torque. The ignition can be used here and on many projects to come. This should improve the exhaust efficiency and the ignition, but you are not improving the intake side, so the overall effect will be limited. To rebuild the carb. is a good way to get performance back up to stock, but a small 4bbl will give better power and MPG, provided you can keep your foot out of it. <O</O
I found my intake used. I am trying an old Offenhauser dual port that splits primary and secondary ports in the intake. This is thought to increase velocity, power and MPG... And a 600 Edelbrock that I got cheap…We will see.<O</O

 

but that means id have to get a different intake?
and i was thinking of getting the headers then making some side exhaust pipes , maybe adding flowmasters?

 

If you dont want to change the 2bbl intake, at least go for something like the holley 500 (550?), the biggest 2bbl you can fit and really good for the down low stuff. edelbrock performer manifolds for 400's whilst aren't as plentiful as other engine sizes arent that hard to come by and not that pricey either although you would definitely need another carby then so it would depend on the budget.

 

Yep, You have to get the air in before the exhaust can move out. If you are removing restrictions on the exhaust side, you will want to remove them on the intake side also. Otherwise there wont be enough air coming in to justify large exhaust gas going out. The next restriction in this line is the valves, or the opening of them, to allow air/fuel in and exhaust out of the heads. This means a cam or in my case I am going to try some 1.8 roller rockers on the stock cam.
Good luck

 

If you've got the bucks to spend, the Edelbrock Performer Package wakes these motors right up! It would've been a breeze to do when you did the heads and timing chain, but now that you've been in there you're over the learning curve, and it would be no sweat to get in there again.

If you haven't got the bucks - or want to drive it a while before you dive into it again, you can mount a 600cfm Carter/Edelbrock/Weber AFB on an adapter plate. Mr. Gasket makes the carb adapter and Edelbrock makes all the pieces to make the linkages work. I know most guys will cringe at this, but I've done it on both 390 and 400 engines, and got a noticable increase in power and a DRAMATIC increase in gas mileage. The stock Motocraft/Autolite carbs are junk, and if you have a reman on there it probably has the wrong jets in it. The AFB is a very forgiving carburetor, and you can still use it when you upgrade the cam and intake.

 

Interesting, I didn't think you could go 4bbl to 2bbl with an adapter. only thought you could do it the other way around. It is Friday morning here though so may be missing something (like a brain) LOL.

 

Same adapter, just upside down! The first time I did it, I was just desperate to get the crummy remanufactured Motorcraft off there. I was going to put a Holley 2300 on there, but wasn't real exited about dealing with the typical Holley power valve issues. Then I realized that the 2300s came in 500 and 600 cfm versions. I thought to myself, "If the 2 bbl manifold will flow 600cfm then why wouldn't a 4bbl work?" I already had the Edelbrock 600cfm AFB, the Mr. Gasket adapter was about $30, and the pieces to adapt the throttle and kickdown linkage were probably another $30. It worked awesome! It was like I'd put a completely different motor in the truck!

 

Still trying to work out where the extra 2 barrels on a 4bbl caby go to on a 2bbl manifold? is it a taller adapter that squeezes the 4 ports on the carb into the 2 ports on the manifold like a funnel?

 

Correct. It's made by Mr. Gasket, you can probably find it at Summit...

 

Interesting. The smaller ports would massively increase air velocity. If you wanted to fit a 600 cfm carby (no bigger) and already had one something to consider. will look at now

 

The 2bb manifold is basically two toilet bowls, the ports are so large. Also, the 4bbl throttle butterflies open towards the middle anyway, so the 'funnel effect' isn't as dramatic as at first you'd think. The increased air velocity is probably why the gas mileage increases dramatically. It's effectively sucking through a smaller carburetor - until you kick the secondaries in!

 

found them. Not as funnelly as I thought. would have to worth a lash if money was a drama and making baby steps. You would at least be able to see the difference between each change and know exactly what improvement does what.

 

So i can get a big 2 barral or 4 small barral carb and not hurt my gas mileage?

 

I went with the Edelbrock 600cfm AFB on both my 390 and my 400, and the mileage improved over the stock 2 barrel in both cases. Then, if you decide to put the Edelbrock Performer cam and intake on later, you can still use this carb.

 

One thing I noticed that was not mentioned was addressing the oiling system issues these engines were plagued with. The problem with the 335 series V8s the number 4 and 5 mains were the last bearings to get oiled. This why these engines seemed have such a short life span. I read in a High Performance Ford V8 book I have, if you run and external oil line from the port on the front of the block to the the port at the rear, this helps a ton. Before you start trying to push big power numbers, make sure it's gonna hold together first.
John