Good Video as usual.

Bearing Bob wrote:

Well done Day. What pistons are those?

It’s a KB364.030. Looks like summit has them

My rebuilt. engine has the same silicon skirted pistons also. Only .10 over stock. Thanks for the info. on ring thickness!

I think if you are going to use factory heads there are really only two options, E7 with some gasket matching and maybe some milling to up compression (I have a set of E7s that I have done that very thing to) or GT40.  In this day and age with all the aftermarket options the only reason to ever do a cleavor IMHO is the "cool factor"  or if trying to keep something original like boss 302.  You will likely spend more converting to Cleveland heads than what a set of Flotek Windsor heads will cost you.  When the Cleavor was invented it was because the only SBF options were what Ford was making and so you had to modify somthing from another engine to get more power.  Now with so many aftermarket heads available you can get aluminum heads that will cost less and perform better than the Cleveland swap.  I can't however argue with the "cool factor" or the "because I can" factor of a clevor... I do see the appeal its just not the best option $:HP

6sally6 wrote:

Greg B wrote:

s
Edit:  I did the math and played the numbers and flat tops with a 69cc head(even if you lucked into some that someone did a bunch of work on or had knowledge and access to a machine shop) is still 12.49 to 1.   total nothing burger idea.

Dished pistons or even large valve relief pistons may help control the compression monster!
6sal6
 

What I was looking into was using stock used 302 or 5.0 if you will HO pistons.  Throwing a total low buck engine together.  90% of the money would be in the eagle crank and balancing.   It leads to a total compression challenge.  I even tried researching if one could dish factory ford pistons a bit on a mill but there really isn't much information available.  There would be if those creative guys in India drove Mustangs.  Lol.   Anyways...

I need to go see just what casting of E7 head I have down there.   I had assumed they were PAs because they had 1/2" bolt holes.   But it looks like E7 chamber cc's are all over the place depending on your casting.    I still think I'm better off just leaving this a 351.   I've now gathered up my oil pan and I cobbled together 16 brand new lifters cheap off eBay auctions of leftovers and such.   So I have about 20 dollars in those!    I've just about got everything together to put together a total low dollar engine with stuff I've had around forever.   It will either run, or it wont..lol.   
 

Stock 351W heads were designed for a 302 sized motor.  Why Ford thought they could slap them on a 351W is beyond me.  At the very least they should have installed larger valves.  I believe stock heads are one of the biggest limiting factors on the performance of a 351.  While good for a 302 and adequate for a stock 351 you will be starving a 393.  I would predict that at lower RPMs you would get massive torque and really good power so if that is your goal it seams like a good idea, but above 3500- 4000 RPM the motor is going to choke and fall flat.   Think about how much room there is for improvement in the heads on a 302.  By replacing the stock heads on a 302 with good flowing heads you can bolt on 50-60 HP depending on the cam and intake.  That shows how restrictive those stock heads are.   Now put those same restrictive Ford heads on a 393 which has 30% more displacement and it will be like trying to take a deep breath through a coffee straw.   Your idea is very intriguing.  Getting a set of 69 CC heads and then doing as Sal suggested and opening up the chamber would probably get you to a workable compression.  Adding an aggressive cam would help and then you could even do some gasket matching and port work to improve flow but the tiny valves will still have a massive restriction on flow. The area of a 1.71" valve is 2.29"  The area of my 2.02" intake valves is 3.20"  That is almost a 40% increase in area.  Don't know that it will flow 40% better but it is at least proportional to the engine displacement.