Rebuilding 350 motor, questions on some internals

Ok, I have a few questions. I'm rebuilding a 350 block that has been untouched.  Still the orignal bore with all orignal internals.  I'm going to be using the forged crank from the 350 which is a 3.48 stroke with 5.7" rods.  Now, I'll be using my 400 heads that I have and putting them on the 350.  The 400 had a stroke of 3.75" and it had 5.7" rods on it.  My biggest concern is I want to keep the compression around 9.5 to 1 because I plan on putting a blower on it in the future so I'm unsure about what pistions to get for the 350.  I guess I'm referring to the compression distance while looking it up on Summit's website. Any help or advice from anyone?  

Well the 400 heads are bigger because the bore in a 400 *** block is .125 over the 4.0 bore of the 350. Those heads once installed will drop the compression even more because of the bigger combustion chamber. If you still want to use the 400 heads than I suggest you look into flat top pistons. My most respected companies are Keith Black and Speed-Pro or to make it easier on the process you can get a nice forged set from Eagle Specialties they sell the whole package: crank. rods. pistons, bearings, bolts, floating piston pins, and rings to boot. If you want tips to make the compression high with your 400 heads here are a couple suggestions

1. Buy a thinner gasket than stock. The closer the heads are to the piston at TDC (top dead center) the higher the compression ratio.

2. Mill the heads. Milling is the skinning of the most outer layer of the head on the combustion chamber side. It makes the combustion chamber smaller and will bump up the compression.

3. The shape of the valves. If the valves are recessed or dented in the compression ratio will drop. But if the the stick out farther than flat the compression ratio will bump up slightly.

4. The shape of the piston. If the piston is dished it will drop the compression ratio. If they are flat it will make the compression go up from dished and then domed pistons are the highest compression ratio that usually start at like 11:1 at go up to 14 or 15:1. If I were you I would stick with the flat pistons they would give you the compression you want.  

you do not want to use your stock heads, unless you don't care about performance  

Flat top pistons would be the best for getting your desired compression.  

As for pistons, I would suggest Mahle.  They cost a little more, but they are lighter weight then most brands.  

And I agree with stempak on the heads.  If you got the money then you would be much better off going with some aftermarket heads.  Or even Vortec heads.  Especially since you want to install a power adder later on.

And you don't have to break the bank on heads either.  Vortec heads (would be an improvement) are not that expensive.  World makes some pretty good heads as well that are relatively inexpensive.  
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