Thread: Another newbie needing SBC 350 build help

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Originally Posted by Camojimmy

Spoke with the shop yesterday. They said they do measure on all corners and plan to mill it down to 9" as you mentioned. We discussed which gas I wanted to use and the compression ratio I'd end up with. I'm looking to stick to 87 octane as it's easy to find around me and the compression ratio will be somewhere around 9-9.5 to 1.

Make sure you can get the stack of parts you want before the shop cuts the block deck height. Get the stack first, then cut the block decks to the stack.If you cut the block decks without having the stack of parts in hand, then you may not be able to find the right parts to fit the block. AGAIN, BUY THE STACK OF PARTS THAT YOU WANT TO USE FIRST, THEN CUT THE DECKS TO FIT THE PARTS.

As far as the static compression ratio, if it were mine and I wanted to run 87 octane pump gas with a carburetor and no electronic controls on the motor, I'd be pulling the SCR back to 8.5:1. Proper choice of parts with EFI and all electronic controls on the motor would allow you to run more SCR, but I would be afraid of building a motor that would detonate on 87 if I used a carburetor.
With 8.5:1, I'd use a cam something like this Crane hydraulic roller. You can use anyone's cam that you want to, but I would use something pretty close to these specs if I were building the motor for you.
https://www.summitracing.com/parts/crn-119811

And furthermore, truth be known, if I had a 9" stack of parts, I would probably cut the block decks to 8.994", allowing the piston to push out the bore by 0.006" so that I could run a Fel-Pro 1003 head gasket (0.041" compressed) and set the squish/quench at 0.035".

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op, at that compression ratito goal of 9-9.5 with 70cc heads, 3.48 stroke, .040 h.gasket, standard bore, and zero deck, i'd say look for pistons with 6-10cc. you don't necessarily have to zero deck it to 9 as you have some play allowance alloted with the head gasket you choose. For instance you could deck to 9.010 and use a .028 gasket.

I'd get familiar with learning all you can from SCR to P to V clearance. Good thing is you've found a great site to learn all of this, but i'd learn about these concepts all i could if nothing else, for knowledge sake

The only parts I've purchased so far are the heads. I already had all the other stuff. Also got a new power steering pump to replace the old leaky one, and a few other things just replacing worn out stuff (mounts, fuel lines, etc.)