I bought a block used it had been deck
.is there anyway to tell how much was taking off. Going to order new pistons some pistons set higher than others.

 

The only way to know is to measure from the crank centerline to the finished deck surface. Your crank throw, rod length, bearing thickness, piston side clearance (rock) and pin height determine your piston to deck clearance, depth or protrusion. Can you see remnants of the VIN stamp? Do you have a known rotator to mock up?

Brandon Unklesbay
All-In Performance, LLC

 

They usually only take .005 off the deck when decking a block. I would order pistons that are not destroked and check the deck height once assembled. If your pistons are up out of the hole you can use a thicker gasket but I bet you will be fine as is.

 

Is it a complete long block, short block or a bare block?

Tom

 

Bare block

 

To measure it yourself, use a pair of 12 in. Calipers and a Dial Bore Gauge. Be sure to measure all the cylinders. The height will vary slightly between the cylinders. Stock SBC deck height is 9.025 ".

1. Install main caps without bearings.
2. Measure the main bearing bore.
3. Divide the bore measurement by 2 to find the radius.
4. Hook the jaw of the caliper on the main bearing bore.
5. Measure up through the cylinder to the deck surface.
6. Add the bore radius to the caliper measurement
7. This is your deck height

Tom

 

Thicker gasket maybe adverse to quench

 

If you want to build it right, don't just throw parts in it. Measure the deck height and go from there.

Tom

 

you have to be pretty good with those measuring devices to see a plus or minus .005.
some blocks may have been cut only once, and others a few times depending on how many rebuilds. Thats the risk of buying used.
buying specially cut pistons or rod lengths will cost you more than the money saved buying a used block. your cheapest and quickest solution is to buy custom thickness head gaskets.
decking a block is almost always unnecessary and usually only needed to make the machine shop owners boat payment.

 

Most of these engines are rebuilt with standard automotive head gaskets which are all .039 thick even though the factory metal shim gasket was .015 thick. If you put the non destroked factory type pistons in your block and they protrude a little you have the aftermarket standard gasket option to gain the needed clearances. I doubt highly any block was cut more than a standard .039 gasket would correct. No doubt quench helps an engine run well but as stated, most of these engines are built with the aftermarket standard .039 gasket and those engines are out there running just fine. The aftermarket builds all engines with the thicker gaskets for just this reason, they do not know the history or how many times the block and heads have been worked on.

Best case would be take your block and have it square decked and have them give you the actual measurements then you know you are starting with a block that is exact on all 8 cylinders and know your deck height. That costs money but for performance builds it offers extra performance. BTW: Factory brand new engines were not perfect, many were way out of spec for deck heights and they all ran, some just ran better. This is why people pay to square deck blocks before a build.