Hi - I don’t know I will ask him. Also, this mechanic (with 45 years of experience and he seems to know his stuff and came highly recommended) is insisting on NOT using a head gasket because he insists they will inevitably leak and is having the heads machined to insure a tight fit. Has anyone heard of this?
No.I never heard of that and in fact, I doubt it.
Head gaskets compressed are normally around .035". There is a clearance that you need to maintain between the top of the piston and the bottom of the head. That number is a minimum of .035".
The top of the pistons are normally around .012" to .015" down in the hole. If you eliminate the head gasket, you will only have at most .015" of clearance. With that clearance, the pistons will hit the heads.
You need a head gasket of at least .020" thick to maintain the minimum piston to head clearance. You can shave material off of the head or block surface but you can't add material too them besides a head gasket.
All surfacing of either would need to consider the "down in the hole" and the intended head gasket thickness.
FE's do have a weak/leaky spot both for oil and water at the extreme ends of the heads. There is both an oil drain back hole there and a water passage.
As a result, surfacing the heads is beyond a good idea, it's almost mandatory to make sure they are as flat as you can get them especially in those areas. This is also where many engine builders will apply head gasket cement even on a head gasket that does not require it.
I'd recommend considering a new cam and looking for one that is a "reproduction" of the 428cj cam. Many manufacturers make them. I don't have a specific part number for you but search on line. Many manufacturers have their catalogs up on the 'net.
You NEED to find the cause of the bent push rod and bent valve. While the heads are off, they should have fresh surfacing to the valve seats and valves.
If the heads have not had hardened valve seats installed DO NOT HAVE THEM INSTALLED. That's a GM thing since GM uses a softer grade of cast iron then Ford does.
In addition, Ford FE heads are very thinly cast between the intake and exhaust ports. You DO NOT want to further weaken them in the valve pocket area. Cutting in for valve seats will weaken the heads there. Not strengthen them.
Personally I'd tell you that if you want to improve the heads while they are apart, have bronze valve guides installed in them. If it turns out that the bent valve is frozen to the cast iron guide, that is further evidence of the need for the bronze guide. The bronze guide will not rust and bond itself to the valve stem.
It wouldn't be a bad idea to change over to stainless valves at this point either.
I'd also change the stock push rods to the hardened type. They will be black vs. silver colored metal. It's pretty difficult to bend them.