Hello, I built a 427 with C4AE High Riser Heads years ago. Still have it. The Harland Sharp Rockers adjusting bolts are pretty far down (almost all the way) with about a .600" solid cam. I remember reading that there should only be a couple of threads showing below the rocker bottom. Would that "Rule" apply to all rockers no matter what type?  Is that "Rule" even correct. This motor has also broken the end off a rocker shaft with hardly any miles (under 1000 miles). I'm thinking that the push rods are way too short. Thanks

According to drawing there are 3 size spacers. Do you know the measurements of the 3 sizes? How much of an interference fit should there be?

Hello, if the side spacers were lost on a 427 block, is it possible to fit with new ones without line boring if everything else is OK? 
What would be the procedure?

Well, it finally came out undamaged.
I used the PB Blaster & heat mostly. Probably used the torch from under the intake and the front of the block at least 10 times in each spot spraying PB when warm so when it cooled it could get in when the metals are moving & tapping in many spots. Spraying a couple times a day also. Last thing I did was put vinegar on it once after heating then the next morning put an oil filter wrench around the top (really nice fit) and wrapped duct tape around the top as to not damage the casting flipping over so sticky side was out for more grip. Pulled pretty hard then.....it moved an 1/8". Thats when I knew I had it licked. Back and forth for about 30 minutes and she came out. Patience patience patience
What I learned was first make sure the nose of the shaft it not seized in the block. If so free it up with PB Blaster (or similar) with heat.
If still stuck, then you know exactly where. (the aluminum housing is seized on the 2 1/4" wide rings that seat it in the block).
This all, start to finish took about a little less than 2 weeks.

Thanks for all the responses.
Well, the shaft turns now. Timing chain and gears are off and was able to get cam turning with distributor still not budging. Distributor is not corroded. Again, motor has been sitting for decades. I have been putting heat on the block (small bottle torch) where I can get it and tapping case to try and get it to start moving, from bottom and on top trying to get the case to spin. So it's stuck where aluminum touches cast iron in the block. I guess patience and tapping and putting a solution on it (maybe trying your suggestions). At least I know exactly what is holding it in now that the shaft turns.

Hello, I have a distributor that won't budge. Motor has been sitting for decades. I pulled the pan and the distributor gear looks OK (no rust) but the rods do have surface rust. All in all the insides didn't look too bad. Heads are off and intake will move around so it is stuck in the bottom. I pulled the pan and put heat on the nose where it rests in the block as have been tapping the oil pump drive rod (not too hard) been putting PB Blaster on it and it won't budge or even spin on the shaft. It's a CJ distributor so don't want to damage it. Next I'm going to put spacers under the intake (to raise it up for more access maybe an inch or 2) and see if I can get channel locks (with rubber to protect distributor casting) on the part that rests in the intake where the rubber seal is and see if I can at least get it to spin.
At this point I'm willing to listen to any suggestions, Thank you

No description on what "427 CI" is. Is it a 390-truck block bored and stroked? What casting cylinder heads, cam, compression,.??
Amazing

What thickness at what bore are you looking for?