I would not worry about it buy the cam and degree it in and go on with your life. It says works well for engines 8.1 to 8.75 to 1 maybe the optimum may be 10 to 1 or 10.5 to squeeze the extra hp the aluminum heads will allow before detonation BUT 9.3 to one will be just fine.
going up to 10.5 would maybe net 14 more hp and 13 more foot lb on a motor making a little north of 400 through the mufflers you will never notice it. If you ran the car then up the compression they only way you would notice the difference would be a couple 10ths in the quarter you seat dyno will not be able to tell!

Just stop worring!

Don't worry, be happy ! ;-)

Your stroke is off 0.005", his is supposedly off 0.038", that's seven+ times as much as yours. That's why I don't believe his measurements. You could get that stroke by offset grinding 0.040" but the crankpin would be that much smaller then.

So I went back and checked his numbers again. Stated deck height is 10.6299, make that 10.630. The piston compression height is 1.926. That number should be nearly exact. The pistons average 0.071" in the hole. The rods are the familiar LY 535 rods, supposedly 6.768" long c-c.
The crank should be 3.750" stroke which means 1.875 radius.
10.630 - 1.926 - 6.768 -1.875 -0.071 = -0.010"
This means to me that the measurements we got from the OP are accurate except for the "stroke" measurement. Probable causes of the 0.010
" discrepancy are the rods are probably a bit shorter because they've been rebuilt once or twice, the 0.071" down in the hole average is more likely 0.068 and it is possible the crank is a little shorter or the block a little taller than measured.

SO,
1. Calculate your stuff with the published 3.75 stroke.
2. You could stand to take another 0.030 off the block to gain a little more compression. Because your cylinder head is a closed chamber design, you get much less cc reduction cutting the head 0.010" than the block 0.010".
3. Your block has definitely had the deck cut nearly 0.100". This means you're going to have a struggle to get your intake manifold to fit.
4. The Hughes answer on cams and head gaskets was just a cookbook answer. Many board members are using steel shim head gaskets with their aluminum heads. Also, the cam should work fine. I would suggest looking at the Lunati Voodoo line for an alternative.
5. If you just put the engine together like it is it will have decent power and probably run on lower grade gas. Maybe that's all you need?

R.

Whiplash? Really? Seriously?
Do you really want a driver that sounds like that?

It seems to me that the whiplash and the Comp thumpr cams are gimmick cams.

On your engine as you describe it I'd use a Lunati Voodoo 60303 or even 60302 if you have piston to valve clearance problems. You have very nice flowing heads and don't need a mondo cam to make great power.

R.

Thanks Dogem,your answer contains a lot of good info ,cause we are here speaking about CR,strokes,etc but in the end ,the question is always the same : How much Power am i going to loose or how much am i going to gain.


@ Dogdays

The bearings are .010 under

Forget the rods cause it has been my fault.I didn,t make a good meassurement.

@John
Do you mean to push the piston by hand?I have tried it and there is not any clearance..
As you can see the engine has been rebuilt,that is why it is so clean.
It has new rings, main and cam bearings etc The cylinders were also honned and the pistons&rod aligment checked and cleaned with sand.These was a couple of years ago,and it has been on the engine stand since then.
Hughes didn,t said that i need more CR for their cam.It is made for low comp engines.
They said that 9.3 to 1 is too low comp using alu heads,and i should to shave them at least 0.050".

As far for the straight edge i don,t have one,but i don,t think the block is wavy,it was straightened when it was rebuilt(At least is what the bill says) but there is too much diference between cyl decks and it will need to back to the machinist.

@Stanton

I have checked all the cyl decks again.Three times every one (Just in case) using the dial gauge for getting the exact TDC and using feeler gages.
These are the exact decks:

Cyl 1: 0.070"
Cyl 3: 0.070"
Cyl 5: 0.070"
Cyl 7: 0.066"

Cyl 2: 0.062"
cyl 4: 0.062"
cyl 6: 0.062"
cyl 8: 0.062"

What means that you and Dogdays were right.
The driver´s block side seems to be 0.010 higher than the passenger´s one,so i suppouse that a visit to the machinist is going to be a must.
i will ask him for leaving all the cyls at 0.062".


Thanks