How sketchy are the stock valves?

Regarding replacing the factory valves...

If buying any of those listed above in the stock size, is that something you can just pull out of the box and lap in at home with any reasonable likelihood of success or should the heads be taken to a machine shop to have it done properly?

Great thread here. I just bought a set of 4V heads (D1AE closed chamber) that I need to take apart to see what has been done to them. Looks like the guide seals were changed but not sure if the valves are still OE, if they are OE I will be changing them. Interesting to see the mention of Alex's Parts in this thread, I was always surprised and frankly a bit leary that their prices are so low, yet the reviews (as 4VANDPROUD mentioned) were pretty good. 

If you are going to pull the engine for this work, have someone check valve-stem-to-guide clearance to ensure new unworn valves fit properly. With all OEM iron heads, the valve guides are part of the casting. To use replacement guides, the originals must first be drilled out, the holes reamed to size and new replacements pressed in, then reamed again to valve stem size. Or you can have good guide bushings installed and avoid the drilling step. All this at about $100/hr costs $$$$, which is why it's often cost-effective to buy new aluminum heads that already have the guide work done, a competition valve job and  thick, flat, uncut deck surfaces. They will be configured to Boss-351 specs.

Plus you lose around 30 lbs from each head, which makes later working on an installed engine far easier, and you gain better airflow & more power from repositioned intake & exhaust ports. But if you do this, stock headers will not bolt on without rework. If the wt savings interests you, another 40 lbs can go away with a matching aluminum intake & aluminum waterpump & pulley, to total over 100 lbs gone from your engine. That's like NOT always having a passenger riding with you, in terms of fuel mileage and performance gains.

Note that nearly every advantage above becomes iffy when cheaper chinese castings and/or valves are involved. Also note that ''CHI'' brand aluminum heads are made in Australia and are fine to use. If you paint aluminum heads Ford-blue, all but the most anal onlookers will think it's 'stock', if that matters to you. One early racer (who shall remain nameless) once used a coat or two of iron-based paint, then Ford blue on top so a magnet would stick to his alloy heads during inspections. If your locale still has smog checks, this could help.

I would certainly enjoy not having to heave those heavy beasts around again.  I took them off the engine solo with the engine still in the car.

Are there aluminum heads that will work with my existing headers (that bolted up to the factory heads)?

They look like these.  I thought they were Hall big bore headers, but not sure given the independent flanges.

Those look like GTS headers- stock on Euro Gr-3s and sold by Hall but not Big-bores.

I seem to recall Tim Meyers making aluminum heads that are identical to the stock heads. 

Was that perhaps Scott Cook instead?

http://www.scmenginedevelopmen...cleveland-heads.html

Ah, yes. It would be Scott Cook.

Perry, stock iron 4V heads weigh 60 lbs each plus the weight of all steel valves, springs, retainers, pivot-studs & rockers.  I use block studs to hold the heads  more securely against blown head gaskets but they preclude pulling even my aluminum SVO heads with the engine in the car. As for those stock GTS headers not fitting some alloy heads, it's the bolt pattern in the header flanges that doesn't match up. If you own a drill and some hand skills, that can be remedied at home- as I did on mine in the '90s.

Ok.  Good to know.  I definitely have a drill.

I am still not sure these are GTS headers.

The collector looks different from the GTS headers - at least the ones sold here (I don't have any other frame of reference, so you guys that have been doing this longer than me may know better).
http://www.precisionproformance.com/ex1015.php
Also at Hall:
http://hallpantera.com/cgi-bin...a-inc&item=22780

The ones in the attached photo are like mine (from an eBay ad).

Here is an old post where the 3rd message shows a ceramic coated set like these that the owner thought were Hall Big Bores...
https://pantera.infopop.cc/top...ig-bore-headers-used

These are the AL heads I want  Because My 4v heads with the dot and quality parts makes a mushy bottom end. https://www.trickflow.com/parts/tfs-5161t003-c01

Here's a good example of why you want to change out the stock OE valves. Not

my motor, just saw it on the 351C.net site.

Been there, done that.  You don't want to take a chance.

FYI you can get a new set of Severe Duty Stainless Racing Valves from SI Valves for $160. They will have a shipment of 300 sets coming in around mid to late December 2019. Also as many have said valves from a BBC  will fit the Cleveland 4V heads.

Be careful with cheap on-line BBC valves; OEMs had 3/8" valve stems while aftermarket are 11/32" and will fit a 351-C. I suppose one could have stock Ford iron guides bored out to 3/8" and gain considerable weight- which will limit rpms. Stem lengths also vary, making pushrod length a variable as well with such a combination. To use an adjustable valvetrain, the engine needs hardened pushrod guides so at least 3" of one end of all 16 pushrods will need to be hardened. Stock 351-C pushrods are not and will wear in two, while spreading steel scrapings throughout your engine. There are no cheap shortcuts in building a 351-C.

Check your "ss" valves for magnetism; some places weld ss heads to plain steel stems so some parts of such a valve will be magnetic. What we're advocating is NOT having a weld (and potential failure at speed) to deal with, not whether there's stainless in there or not. And there are some odd mixes of stainless steel that are no good for severe service like in an engine valve. A few will actually rust and are weakly magnetic. Far east backyard shops also make up their own "grades" of stainless and other metals that the SAE have never seen before. Name brands with years-long good reputations are best.

Hi Jack...good advice as usual. I checked my valves that are out for a head rebuild (71 4V) and very interesting, the intakes are VERY magnetic, yet the exhausts (with rusty tips) are still magnetic but barely. I would love to know what they are, but the heads have been rebuild and there are things I don't like, so anything but the actual head casting is likely going to be replaced.  

Way back in the mid-60s, GM, Ford and others used a nickel alloy for the hotter-running exhaust valves, welding them to a mild steel stem for penny-saving. My '65 Corvair had such exhausts that were thus magnetic only on the stems. Back then engines seldom turned even 6000 rpms so most owners didn't notice the weld was a potential weak spot. Except on hard working air cooled VWs or 400 Ford motor homes climbing a long hill in summer towing a trailer....