Originally Posted by 57Chevy3100
Im building a sbc 350 bored .060 over to put in my 57 chevy truck (5500lbs). Im using a Magnum Flat tappet comp cam (.499 lift, 270 duration), Sealed Power hypertonic flat top pistons, stock chevy heads with 1.74 in, 1.50 ex valves with comp cam recommended valve train components, performer eps intake, Holley 650cfm electric choke vacuum secondary carb, and its in a 010 4 bolt main block. And behind it is gonna be a 2000 stall 2 speed powerglide. What I'm wanting to know is if these parts will go good together and is there any changes yall would recommend I change keeping in mind this will be kind of a budget build? Oh yea I intend on using as weekend driver street truck and where I live emissions are not a concern as far as being checked.
I'm thinkin' that the curb weight (sittin' at the curb with a half tank of gas and ready to drive) is about 3360.
What is the casting number on the heads? It's under the valve cover, in between the valve guides and should be a 6, 7 or 8 digit number. Chances are pretty good that they are 3998993 heads, but I'd like to know for sure before I post my opinion. Also, if you measure the intake valves again, I'm pretty sure you'll find that they're 1.72", not 1.74".
To help you further your education, let me explain the piston type for you. The correct word is hypereutectic (high-per-you-tech-tick). It means that the material the pistons are made from has a very high silicon content mixed in with the aluminum alloy.
Hypereutectic piston - Wikipedia, the free encyclopedia
Piston diameter growth from heat is minimal, so that the piston can be fitted to the cylinder wall with very little clearance, usually around 0.001" to 0.0015". These pistons are cast, not forged and fall into the middle of the range for taking abuse. Cast pistons are the cheapest and most brittle, then hypereutectic pistons, then the top of the line is forged pistons, which will take the most abuse. Forged pistons will also grow the most from heat and are normally fitted very loosely to the cylinder walls (piston to wall clearances of 0.007" to 0.008" are not uncommon.