Looking for intake manifold recommendations for my 1966 352 FE in a 1955 ford f100. Rebuilt motor .030 over with RV Cam, cast iron four barrel intake, electronic ignition, sanderson headers, C6AE-R heads. I think flat tappet lifters. C6 transmission
Bought the intake comparo book but it's a little over my head with the numbers. Leaning towards Edelbrock performer RPM. Any suggestions would be greatly appreciated.
Thanks in advance.

 

I'm guessing you mean Jay Brown's book? In it, I believe Jay says the Performer 390 makes more power than the Performer RPM up to around 3500 rpms. At that point, the RPM catches the 390 in terms of power and then leaves it behind. So if you plan to live at 3500 or below, then the Performer 390 is better. If you need the higher rpm power, then the Performer RPM is better.

Many folks in the FE world will tell you the RPM is all around better, but....many folks focus more on what happens above 3500 and a lot of the dynomometers can't measure below 3000 rpms so they don't have any data there.

Also, because the Performer 390 makes more power below 3500 rpms, it stands to reason it will provide a hair better mpg. I believe this is because its smaller runners do a better job of mixing the air and fuel. The RPM has larger runners, which help with velocity at higher engine rpm but will not mix the air and fuel as well at lower engine rpm.

 

Also in Jay's book I don't think that they do any of their testing on an engine that's as small as a 352. With that size engine the intake with the smaller runners is probably superior across the entire engine speed range.

 

Thanks for the feedback! That all makes sense. I really am focused on torque as I don’t feel safe at high speeds with no seat belts in a pretty old truck and I’m enjoying the seat of the pants kick on initial acceleration. I really need a tachometer. I feel like it can wind up pretty high between shifts up to around 60 mph but I’m not sure where my transmission shift points are, RPM wise. Regardless, sounds like the edelbrock performer, not RPM, would be best. Any other options before I pull the trigger? Currently has a cast iron, I think out of a tbird, but it’s got a leak on the rear and a nice polished aluminum would look sweet and be much lighter. Is it normal for the carb base mount to be perfectly flat and not tilted forward or back? Looks like many are. Thanks again.

 

Thunderbird intakes are made with the carburetor bases parallel to the crankshaft. Intakes for other FE applications have an included angle to allow the carburetor to sit more level.

 

Interesting. I’m going to throw a level on my engine and carb base out of curiosity. Are engines usually lower in the front or rear? Kinda made up my mind on the intake but leveling a carb base is just an interesting concept that I’d like to understand a little better.
Thanks

 

I think that most are about 4 degrees down at the rear. That's pretty typical but there are some that are different. Panteras also have the engine sitting flat and I have modified a few intakes for those to take away the included angle.

 

I see. So the goal is to get the carb sitting level? I'm assuming this is so the gas in the carb bowls doesn't shift.

 

Yes that's the idea. The engine is down slightly at the the rear yet the carburetor is mostly level.

 

The T-birds came with a special 4 degree carb spacer to correct the carburetor angle. I sold one years ago but can't find the part number.
T-bird motors were mounted level to the ground. All others were mounted nose high.

 

An aftermarket aluminum intake will save weight (and your back) compared to a factory cast iron intake (45 lbs vs 90+ lbs). Since we're talking a vehicle with a decent amount of weight and you probably aren't going to be revving it to the moon, a modest dual plane such as something along the lines of a Performer 390 that's made to work best in a idle-4000 rpm range will give you the most bang for your bucks. Assorted knockoff copies of the factory Ford PI intake and the Performer 390 sell for $300-350 new. I'd avoid using any open plenum single plane intake no matter how cheap you can buy it just because you'll probably lose a bit of the low end power.

 

If I remember correctly, the Performer has passages for the heat riser, while the Performer RPM does not.

 

Just completed the top end rebuild of my 390. RV cam, .060 over, 10.15:1 compression, headers. Ran it that way for a few years. Now added Edelbrock RPM heads and Performer intake. Small increase in compression since smaller chamber heads, gasket matched the intake. Still doing final tuning and can't tell you how the intake would perform by itself but.....Holy Crap! This thing will pull a crooked road straight. The difference is incredible.

 

I found the FE T-bird carb spacer number. I knew I had it written somewhere. So figured I add it here in case anyone needs it.
C2SE-9A589-B

 

I run a Holley Street Dominator (swap meet find) which is an open plenum design and it's fine on the low end. So there are exceptions to that absolute.