Cylinder Head replacement

[DeepC73]

Hello,
I am looking at buying a new set of heads for my 1973 5.0, 302. It is the original engine. What type of heads do i need. I am just looking for a factory replacement. The motor is not modded or bored at all. I am looking at SUMMIT RACING, JEGS ETC. Which cast iron heads should be the right ones? Thanks as always guys!

 

[Broncobowsher]

There are no new stock heads anymore.

You are looking at aftermarket performance heads. Or remanufactured OEM heads.

First question, why are you replacing the heads? If they have a crack, ok you need replacment heads. But if they are just wore out many machine shops can rebuild them. Had a local machine shop rebuild my boat heads just a couple years ago and it was only a few hundred dollars. Good as new. Everything fit just like it should.

The new heads you are looking at are all performance heads. If adding performance is what you are after, many are a good choice. Although cast iron is generally way down on the list. For the most part cast iron heads only exist in the aftermarket to fill a special niche, usually circle track racing that specifies a cast iron head to try and keep the entry level classes a little more affordable. Not that the cast iron heads actually do that, but they are trying to do that.

 

[DeepC73]

Local machine shops are wanting $400-$500 bucks to have the heads overhauled. My current motor has 48k miles. Recently I noticed black sutt spray/splatter on the ground by my exhaust pipes on both sides. That black sutt usually means the valve seats are bad. I did a cylinder leak down test on each cylinder. All were either in the good/low category. I’m hoping the leak down test was poor due to bad valve seats, they are 50 years old. I can get a new set for about $50 more than the machine shop job. That is why.

 

[Timmy390]

Local machine shops are wanting $400-$500 bucks to have the heads overhauled. My current motor has 48k miles. Recently I noticed black sutt spray/splatter on the ground by my exhaust pipes on both sides. That black sutt usually means the valve seats are bad. I did a cylinder leak down test on each cylinder. All were either in the good/low category. I’m hoping the leak down test was poor due to bad valve seats, they are 50 years old. I can get a new set for about $50 more than the machine shop job. That is why.

That black is more than likely a "rich" condition and condensation at startup is mixing with the suit and leaving those marks. My 69 Stang does that, My Samurai does that and so does my Bronco....I'm 100% sure none of those have valve seat issues or head gasket issues. None of them smoke. None of them are running cats.....lots of moisture.....

If you have smoke it could be valve stem seals.......

That price is about right for head overhaul. I would verify verify verify before I pulled heads.

Tim

 

[Lawndart]

Unless the engine has been severely abused, those heads are fine. Did the leakdown test reveal the valves as the issue or the rings?? If valves, a weekend, new head gaskets, new manifold gaskets, new valve guide seals, some valve lapping compound and some solvent will get those heads in shape for another 50 years.
Most likely the valve guide seals are hard and mostly broken.

 

[Rustytruck]

The problem with aftermarket heads is the combustion chamber kept getting larger to enhance flow but the piston changed with them to keep the engine running properly. in your original engine you have some of the worse deep dish pistons. so pretty much any aftermarket heads will drop your performance.

Ford Cylinder Heads and Valvetrain Interchange: Small-Block

Ford Cylinder Heads and Valvetrain Interchange: Small-Block- Covers Ford V8 Engine Families Including: Windsor, Cleveland, FE, M, 385-Series, and Boss

www.diyford.com

after about 1975 the stock cast iron got induction hardened seats to deal with unleaded gas. I once did a small block casting adding stellite seats and stainless valves for a 289 that was close to $1,000 back 30 years ago cant imagine what it would be in today's market. so any aftermarket heads watch the chamber sizes very closely if your not changing pistons.

 

[Timmy390]

IF you're dead set on changing.....I suggest a set of E7's or GT40's

Tim

 

[Broncobowsher]

And be prepared that none of you original valve train (pushrods and rockers) will work with a replacement set of heads. Aftermarket or late model. Good chance it is worn anyway. The ball ends on my 60k 460 were about half gone and the rockers had a lot of wear into the pivots.

 

[Speedrdr]

Or if you want to change out heads and $$$ is not a determining factor, get a set of Air Flow Research heads. They will let the engine breathe so much better. They are; however, pricey at around $1,800 a set.

Randy

 

[Broncobowsher]

And the really cheap ones, store brand, china specials. The off-shore quality control is well known for being miserable. If you build the heads with good parts, they can be good. Have enough material in the walls to port away if you can find a head porter who can repeat his work evenly on all the ports. But unless you can do the work yourself, they will cost more than a quality set of heads ready to bolt on in the end.

 

[blubuckaroo]

Hello,
I am looking at buying a new set of heads for my 1973 5.0, 302. It is the original engine. What type of heads do i need. I am just looking for a factory replacement. The motor is not modded or bored at all. I am looking at SUMMIT RACING, JEGS ETC. Which cast iron heads should be the right ones? Thanks as always guys!

Before replacing the heads on a small block Ford, you need to know what you've got for an engine. Differen't years used dished pistons or even raised deck heights to lower compression. If you put a 63cc head onto an engine made for a 58cc head, you'll end up with a really poopy motor. On the other hand, the reverse will pep things up.
If you're working on a small block ford, you need this book. It has a lot of part swap information as well as a ton of assembly instructions.
https://www.amazon.com/dp/0912656891/?tag=cbama-20

 

[bmc69]

Local machine shops are wanting $400-$500 bucks to have the heads overhauled. My current motor has 48k miles. Recently I noticed black sutt spray/splatter on the ground by my exhaust pipes on both sides. That black sutt usually means the valve seats are bad. I did a cylinder leak down test on each cylinder. All were either in the good/low category. I’m hoping the leak down test was poor due to bad valve seats, they are 50 years old. I can get a new set for about $50 more than the machine shop job. That is why.

What complete new heads can you get a pair for for $400-500 bucks? And, speaking as someone who has rebuilt hundreds of heads (auto machinist), $400-500 to fully recondition a pair of them is a pretty good price. Last set of heads I did a complete rebuild on were for a Cleveland went out the door at $850 with new valves. And that was some years ago...

 

[BrettKoenecke]

This is super helpful, thanks everyone. Lucky to have such a resource as you.