I'm not sure now. I'm beginning to worry!!

 

I believe that says 1-2 thou in 6 inches. The "8 max", likely refers to end to end. I'd never use two gaskets, but if there is a thicker choice, I'd use it.

 

I think you're right it's the variance 1 or 2 thou over 6 inches but no more than 8 thou anywhere end to end.

It's hard to measure the 6 inches as the low bit is inbetween 3rd and 4th cylinders.

Anyways I've bought a Fel-Pro gasket which measures about 5.5 thou thick (it's the thickest one I could find over here). I've lightly sanded the block evenly with 1000 grade wet'n'dry to get a good mating surface. It will be going on soon so I'll keep you guys posted, fingers crossed...

 

O jeez. First, are you using a known good straight-edge, and feeler gauges to check for. "It's hard to measure the 6 inches as the low bit is inbetween 3rd and 4th cylinders." Just see which fit's under with the straightedge crosswise. I can't imagine the cast iron slumping 8 thou there. I've seen worse with aluminum, but cast iron? That's new! And second.......any "sanding" or aggregate there is all to likely to end up in the cylinder.

With just oil, or better STP or Marvel oil, you can bring (a pair) up past tdc then down, then wipe it back off, repeat. The idea is to use the oil to "pull" anthing out, that ended up between the top of the piston and the upper compression ring. About none of that is OK!

 

Yes im using feeler gauges and a metal ruler. What I mean is the amount of metal in between the cylinders is less than 6 inches so the 1/2 thou over 6 inches rule is hard to apply. It's down by 4/5 thou in that section. Cross ways is fine.

I've packed the cylinders with towels making sure nothing has gone down them. I was advised by the machine shop not to clean the top of the Pistons and tops of the walls as dislodging this dirt can cause more problems

 

So, across is fine. That makes sense, cast iron just doesn't "slump" like that, with the expected temps. So that 8 thou figure is out the window. Is your ruler one foot, and you are getting 4-5 there in the middle, lengthwise? That might be within the .008 spec. Btw in a pinch/hurry with a head of mine, I actually used mono-filament fishing line one time!