I would like some advice for 430 Lincoln head porting and polishing. Thanks

Hi, you probably don't want to read an answer of that type, but those ol' 430 ports are huge. In fact they a lot too big. Velocity is weak. Those big land jachts need torque'. A lot of torque and smaller ports.
What's your car BTW?, street or strip?

It will be used on the street. Are both intake and exhaust ports big enough. What size header tubes would you recommend? Do you have any recommendations for piston suppliers? I have contacted egge and all they have is flattops. Wiseco wants well over $1000.

As far as I know, correct pistons can't be obtained out of the shelf. They are all flat tops which do no justice to the
M-E-L. Please read this article for more details
viewtopic.php?f=2&t=67

Your correct choice would be custom made pistons by any of the aftermarket piston manufacturers like Wiseco, JE pistons, Ross and others. Some may have your piston design in their archive, some may need your specifications.
Please read this article for info about how to take measurements and so on
viewtopic.php?f=2&t=394

You might want to choose the same manufacturer as forum participant "Chris Craft crazy" has done. This way you might run into the same sales rep. You wouldn't have to explain the MEL design all over and you'll have chances that they still have the CNC program for a MEL piston design. However, you will still have to take measurements from your own block.

I can not recommend any soecific brand on your headers as I haven't fiddled with headers. All I can say is that you will need snakes that are small in diameter and long in lenght. That's a general rule for producing torque on a heavy car.
If you had a light weight funny car, plastic bomber on nitro or with a compressor, then huge diameter short tubes would be your choice. That's just a general rule.

I doubt that a street anchor will ever make a serious advantage with headers. On a heavy classic street yacht I personally would rather spend my dime on a superior brake system such as a disc brake conversion kit.
You can easily make a car run fast, but it's a lot more of a challenge to make it stop.

What's your car BTW. Do you have enough space to mount headers?

Be careful about porting Mel heads, especially early ones. Cores shift and they can be ruined by hitting a water jacket. Theo is right about the ports on the early 58-60 heads. My brother just matched the last 1/4 inch of the ports to the gaskets, blended the lip under the valve seat and ground down the vavle guide bump. He ran an isky cam and the factory tri power and was plenty fast. If this engine is still in a lincoln chassis, you are going to have to get headers custom made. And again this may not be your best choice. Minor upgrades to cam, ignition, carb jetting and exhaust will please you.
Getting power out of this engine should be your second concern, because it is easy. Your first concern should be the drive train. Those early transmissions will not survive high torque and high horse power runs. I promise you will be sorry for trying to use an older transmission. Please benefit from my trial and many errors. You should consider a swap for a 1967 or newer c-6 transmission from a 390 or 428 ford. Depending on the year of your engine, there could be some bolt up issues. Those were covered well in the old forum. Get a 2000 stall convertor and I believe 3.55 gears for the lincoln differential are the only option. Good luck. TJR