Need .030 pistons for a Vortec 350 in 1.56 compression height

[crm318]

I will be building a Vortec 350 pretty soon that is in need of a .030 over bore. I would like to retain the stock 9.5 compression, however, I don't see any pistons put there that have the stock type piston top at .030 with the 1.56 compression height. I do see a ton of them in the 1.54 compression height. If all else fails, would I have to remove the difference off of the block plus what ever it takes to get zero deck? I am looking for this style.

[truckster]

I believe the thinking is that if you're boring .030 over you probably will want to deck the block. I did on mine. To me it's reassuring to have the fresh metal for a sealing surface.

[Warrens69GMC]

Why not just order a new long block?

[Marv D]

Have you cc'd the stock pistons to verify what your looking for? I believe the stock was a 9-11cc dish with the 4 eyebrow and 0.060" recess/ dish.

Ya too many of the builders pistons are a reduced CH which is just STUPID. I don't get why KB and TRW have done that. Making the quench bigger on these motors is not a move in the right direction.

The SpeedPro L2403NF30 will gt you there, but in forged not hypereutectic and a bit pricy at $310 with a slummit racer discount

[Bigdav160]

I had a set of LT-1 pistons and that's what I used in my L31. It had to help the quench over those large dishes in the stock piston.

I also decided on aluminum cylinder heads. No problem with detonation that I know of.

[crm318]

I have a complete and disassembled L31 and I just wanted to rebuild what I have. If I were to use a 1.54 piston, how much deck removal could the block take assuming that it may not even be at zero deck with a 1.56? Not at all opposed to decking.

[Willi2ds]

I just ordered a set of .040 over pistons from Summit Racing 1.56 comp height.
Here's the link for the .030 over ones.

https://m.summitracing.com/parts/sum-17350c-30

[crm318]

Thank you. I did come across those. They may create too much compression as they only have a +6 cc valve reliefs. I would need something in the +12 range.

[Willi2ds]

Originally Posted by crm318

Thank you. I did come across those. They may create too much compression as they only have a +6 cc valve reliefs. I would need something in the +12 range.

What about running a thicker head gasket with them to lower the comp ratio?
Posted via Mobile Device

[Marv D]

I'm pretty sure Mahle has a "D" dish that would build a Zero-deck 0.04 quench motor. I bought a set for my towing 383 / vortec head motor. They were a pretty nice piston with coated skirts floating pin and such. But I'm afraid anything that fits your bill perfectly is going to be a custom piston, (around $650) or your machinist is going to have to cut the dish to exac volume. (=adding $s till it's about the same as a single change piston order anyways) Seems no one I ran across has the exact configuration your looking for in a stock stroke.

[b454rat]

Whats wrong with a little more compression? I ran 10:1 in a TBI 406 running 87. think it pulled harder than the Vortec 454 I had.

[crm318]

I would be running a carb. I just want a cool running engine that can use 87 octane. I will be using the 383HT/350 HO cam. After doing the calculations, I could run a flat top with a thicker head gasket (.051) and it would come out to 9.6 or so.

[toolboxchev]

I will be running the same road soon. Please let us know how you did. I believe Marv has a very good indication of what needs to be done.

https://www.youtube.com/watch?v=A0TalLrtZ24

Let em rip!

[crm318]

I hope to choose wisely!