I am having my shortblock (355) put together by a shop here locally and everyone here says they do excellent work. I have not had any real experience with this shop and I am just taking everyones word for it. However, This is what is being done, Block was bored .030 over, crank turned .010 over. They are installing the freeze plugs, pistons, crank, camshaft, bearings blah blah blah. Your basic shortblock install.

I called them and asked them if they would zero deck the block because It would be easier for me to install the correct gasket height for the heads to get the correct compression instead of trying to mess around with finding the correct gasket if they did not deck the block. The machinist stated that it would be best if I didnt zero deck the block because it would cause my compression to go up and I would have to run special gas etc. He said it costs $45 a side for decking. Is he correct in saying not to deck the block? He seemed to feel that since my pistons are flat top pistons it would be better not to zero deck the block. He said to trust his work and that I would defiantly be happy with the work. He is also installing the timing chain for me as well.

I know he knows a lot more than I do, however I have heard discussions on here stating that zero decking the block was a really smart idea to do.

Thanks guys.

 

In the order, as you presented it...... Your reasoning is 'sound'.... Well, dah... sure the compression will go up, but your already knew that. Special gas? What does that mean? A special color? No... you are using flat (no dome) pistons. What you are actually doing (or attempting to do), is bring the block up to engineering (as intended) BLUEPRINT specs. You will end up with a net GAIN, with the deck milling. Yes, it will increase the CR, but by bringing (as what I consider to be your original intent) the deck CLEARANCE to a 'proper/correct' dimension, will actually lessen the chance of detonation. The reason being; the reduced clearance causes additional combustion swirl/turbulence, resulting in a more effective flame travel/burn. I do not understand his reasoning, as to the use of the flat top pistons, having anything to do with anything. Maybe, you need to 'pick' his brain, a little more.