i,am going to a big swap meet this coming thur,fri,sat,and sun [charlotte,nc] and am gonna be getting a set of 30 over pistons for a 350 4 bolt main block i have and was wondering which pistons you fellows recommend as far as cast, or forged or [spelling hypethpic???? what excatly is the difference.this will basicly be a pretty mild to stock engine, i,ve been doing some research on these pistons, but as a good friend of mine used to say [he has passed away now] i,am not sure i understand all i need to know about this.so could we have a piston school. like i said earlier it is a 350 and will be pretty much stock and is bored 30 over.and as usual THANKS

If you're not going to race this car all the time,and are just going slightly over stock,then the cast pistons should be fine. They should be good to 300 hp anyway. The hyperutetic are a little added insurance,3-400hp. They dont fit as tight as the cast and therefore will make a little noise at start-up. In my opinion the forged pistons are overkill on a basically stock engine,and they are a lot more money. If you were putting nitrous on,I would say sure go with the forged,you would need them to handle it,but not for a slightly over stock motor. they also tend to be noiser then cast or hyper. I used cast in my motor, slightly over stock,intake cam headers and flat top cast pistion,no problems ever. Bob

I would go with hyperutetic pistons. The new ones are good for way over 400 hp and they aren't too expensive.

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Bob
Garnet Red 69/SS396/TH400/355 Posi
94 HD Dyna Wideglide

I recently e-mailed KB Pistons about their strength, here's their reply.

Hi, George;
First, there are two types of hypereutectic pistons. The Silvolite OEM
hyper's have 13% silcon and are T5 heat treated. The Silvolite's would be
good to 400 HP. The KB's have 16% - 18% silcon and are T6 heat treated. The
KB's have unlimited RPM and HP.
Thanks, Tech Dept.

OOOKKK, My 2 cents worth, please.

Make sure you use the recommended ring end gaps for your pistons and I would go forged if you are even thinking about using NO2.

Thats all. pdq67

Bob63 - hyperutectic pistons fit tight and are quiet - I run them in my 383.

Forged pistons are the ones that fit a little on the loose side, but they are not necessarily noisy; cheaper forged pistons ARE more prone to piston slap and may consume a little more oil than stock cast pistons or hyperutectic but often its not noticeable.

I would disagree that the KB pistons have "unlimited HP potential" and although they are very good pistons, I think that's a stretch. I feel safe to around 500 HP with the KB's.

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68 Camaro, 383 small block with TH350 trans. 11.98's at 111mph and never trailered.

i have a set of lightweight forged TRW pistons in my engine, and they were designed for relatively tight clearances. they are dead quiet at startup. all i hear from the engine when it is cold it the very, very slight tapping of my roller lifters, and a couple of exhaust leaks from seams that need to be welded up.

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1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16X8" IROC wheels. 12" Corvette brakes on the way.
see pics here http://community.webshots.com/user/novaderrik

Can the Keith blacks take a small dose of the juice without meltdown?

The KB's didn't have "unlimited" potential in my 406. Unless you call 5500 rpm unlimited. Thats when the top came off of one, and cracked a cylinder. In all fairness though, I probably had it too lean at the time. I've heard they don't like that too much. Live and learn!


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David
68 SS Camaro (377CID, 11.633 @ 115mph)
2001 Track Champion, Modified & Trophy 1 Div.-Wall Dragway, TX.

Go with cast. If your not going to squeeze it. I'm building up a 350 for a suburban right now, and it won't be totally stock. I want a nice tight motor with my torque where I need it. Around 2500 rpm. I'll never spin this motor over 4000 rpm. Cast are cheap and reliable for stock or mildly modified applications.
Now, my little 327 has forged. I spin this motor much tighter, and I have the juice option.
The big block has forged pistons, and they may not survive the abuse I'll give it.
Save some cash on this one. Go with cast.

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Steve
67 396 race car project
67 SS 396,4-sp mothballed for resto
67 RS 327,4-sp
72 RS 350/350, under current resto
69 4X4 suburban 350,4-sp
73 3/4 ton 454/400
Stevo Camaro's Toy (http://www.geocities.com/stevocamaro)
Our Muscle Cars (http://community.webshots.com/user/steve_lynell)