I am building a 390 for my 74 f100. I went through a lot fe motors that friends had on hand to find the 390 I am rebuilding. I ended up with a set of heads that have really big intake ports. I didn't notice until the guy doing the work on my heads and block pointed them out to me. He had a set of fe heads setting next to mine and there is a big difference. We measured them out and the ports are 2.302. I measured my ports on the edelbrook intake I bought for the motor and they measure out at 1.75. My question is will these heads work with the intake I have are do I need to find a different intake to work with the heads. I have another set of heads and the intake ports measure out at 1.56 on them. But I would rather use the set with the big ports if I can find a intake that will work with them. Thanks for any and all help.

 

How big are the valves and what are the casting numbers on them?

 

I don't have the heads to get the casting number off of them right now they are 60 miles away at the machine shop. But I think the numbers where C4AE-6090-G I do have the old valves at my house I will go measure them in a few. Thanks

 

Intake valve is 2.02 and the exaust valve is 1.56. Thanks

 

Head info:

Heads

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332-428 Ford FE Engine Forum: truck heads

Small intake runners into large head ports is not a problem.

Big intake runners into small ports not so good, but can still be done and will run fine, but not what you'd run races with methinks.

 

Thanks for the help. I was hoping that would be the answer. I really didn't want to start hunting down a bigger intake at this stage of the game.

 

A lot of this comes down to "what are you aiming to accomplish", and then it is a bit of art with some science.

From what I've read, for a street engine you should not try to match the floor of the intake to the floor of the port, just a bit of radius work to blend. You can lose low end torque.

What intake are you going to run?

 

I have a edelbrook performer. The truck is going to be a toy manly. I drive it on weekends play with it around town at night. I still have the 360 in it right now. It won't be towing anything more then a bass boat once in a while. I have the crower 16903 cam for it building it at 9.5 to 1 cr. It won't be a real high rpm motor by that I don't need it to rev out to 6000 rpms. I have sanderson ff427 headers and dual 2.5 inch exhaust with 40 series flow masters on the truck. It is going into a swb 74 4x4 four speed. My main concern with the heads intake ports being a lot bigger then the intakes ports was if they would work and run. I think I will have plenty of power out of the motor with out port matching the intake to the heads. Any body with concerns on this let me hear from you thanks.

 

If it is a Performer, and not a Performer RPM, you are leaving a lot of power on the table. There is no reason to be afraid of 6,000 RPM. Lots of fun to be had in the 4,500 to 6,000 space and no reason a well built FE can't do it.

I don't know what the cam characteristics are, but with a cam that is a little on the aggressive side you can get lots of torque but also make good horse power. Horsepower means RPM.

I think the mismatch on the intake runner floor height to the port floor height will work in favour of low end torque. Think about a different intake. The Performer has the advantage of being light, but it is no better than a stock intake.

 

Time to flip the coin over and look at the exhaust ports. Your headers may or may not line up with the exhaust ports. You need to measure from the bolt holes to the exhaust floor and roof, then compare those measurements to your headers.

.02

 

I bolted the headers to the heads right after I got them and before I sent the heads to the machine shop. They looked like they will be okay. I should of done it with the intake also but didn't even think of a miss match there. One thing about taking on a project you learn a lot of new tricks for the next one.

 

sounds like you have earlier FE heads 63-65 , have your guy gasket match the intake ports , real simple to do with a die grinder and a burr or stone tip .

 

you want to measure the combustion chamber ! some old heads only had 60cc while later had 72cc etc makes a huge difference when calculating your compression ratio
link to help How to Choose Ford FE Engine Factory Cylinder Heads

 

The combustion chambers measure out at 74 cc. We measured them before the pistons where ordered. The link to Barry's page is a good one thanks.