I just got my 350 bored 30 and crank turned 10/10. I'm want to use the 416 heads (305). I've polish combustion chamber and clean port casting. No porting.
Pistons are flat top 4 valve release (h345dcp). I know my compression will be high and hope to get the heads to around 62-63 cc and run 93. Cam Is a melling Mtc-1. Pistons are in the hole .036. Head gasket is .039
This engine will go in a s10 5speed daily driver. Just after efficiency and dependable.
Engine will run on tbi and EBL flash and use 93/110 mix to break cam.
1st Q's is how much should I deck it for the quench be "efficiency" but not cause problems with intake gasket/alignment.
2nd is should I use a stock 350 bin with lil timing taken out and be ok to break the cam in?
3rd is around about what would the dynamic compression be
I'm sure I'll have more q's.

 

"Destroked" junk "rebuilder" pistons. Short on compression height. Forces you to take excessive material off the deck to get acceptable quench/squish distance.

 

The block is torque bored to these Pistons.
Should I get more new piston with 1.56 and use thinner head gasket or stick with these new pistons and get .030 taken off.
What threw me off I guess is the piston has h645dcp/h345dcp.
H645 is 1.56 and h345 is 1.54
Why is both numbers on the piston meaning 2 difernt things

 

So it's .030 over. Not a big deal.

You should find out how much has to come off the block to get it square side-to-side, and front-to-back. Then figure out how to get to zero-deck. I suspect you'll want pistons with a taller compression height measurement--1.56 or even a bit more, depending on availability.

In the end, you need to be at zero deck with a block that has the decks square to the crank, and to each other.

Are the numbers on the piston, or on the box? If they're on the box, the box is probably printed to accept either of those two part numbers. My research (looking up your piston's part number on the Summit web-site shows that those H345DCP pistons have too-short compression height--1.548".

http://www.summitracing.com/parts/slp-h345dcp

Oh, yeah. Another thing:
Why would you use high-octane fuel to break-in a camshaft? Part-throttle, no load...no reason for octane concerns.

 

#2 and #8 is .036 and #1 and #7 is .040
As far as mixing gas I just wanted to be save. I've played a lot with EBL but it was a stock 2.8 to learn on. I know this isn't much of a motor but I was told compresion would be at 10.8-11:1 with 58cc and flat tops.
My head is at 64cc but havnt done the other yet.
The top of the piston has W357 PA06 1 and at bottom H645dcp/H345dcp .030.
When I checked them they are 1.54.
So I'll be ok to take off say .035 and carry intake to shop with block?
I'll use 93 now that you said that. I wasn't thinking about no load.

I had a 383 put together yrs ago that held up about 30miles after cam was broke in. Later I was told compression was too high with 64cc heads(sportsman II) broke top piston out so mabe I'm being to carful as I've never built performance engine, but several stock

 

 

So we know the block isn't square.

Interesting. Far as I can tell, the 645 has slightly taller compression height and is sold in 6-packs to fit the 4.3L V-6.

Not my first choice.

You'd do better to get pistons with a taller compression distance, then mill the block the minimum needed to both square it and get to zero-deck. This will require less (or no) material removed from the intake face of the heads, or from the manifold.

 

I belive I'll get the H631cp pistons (1.56 compression height)
Will I'll be ok to go ahead and send block to shop to get .016 off one side and .020 off other or should I wait on the Pistons and recheck?
With these Pistons at zero deck and 64cc heads with .039 gasket, compresion ratio at 10.4?
I'll be ok on 93 with melling Mtc-1 cam?
To break the cam in could I just use a stock bin for 350 with EBL?