[Cliff R]

The last time I looked at either one they had 8 round pistons moving up and down in 8 round holes.

It's what you do with the compression, intake, exhaust, head flow, combustion chambers, camshaft selection and very close control of timing/fuel curves that make an engine what it is. There are parts out there to do pretty much whatever you want to with an Pontiac engine build IF you can quit using "old school" mentality and get away from traditional myths that abound on the Internet with these engines.

What is harder to do with a Pontiac build is to lighten up the spinning and reciprocating weight and come up with improved bore to stroke and rod length to stroke ratios AND have ultra-light components at the same time.

The LS and even the older SBC stuff will be superior in that regard but on the top side we have some excellent cylinder head choices with modern combustion chambers.

My own 455 is 11.3 to 1 compression and has lived just fine now on a steady diet of pump gas, even 87 octane sine 2009. Yes, I've ran it on 87 octane and it never pinged or even acted like it was going to ping. I still keep higher octane in it just to give me a "warm and fuzzy", but it is flawless everyplace if/when I've used it other than every once in a while on a really hot/humid day fully heat soaked it's tried to "run-on" a couple of times.

What folks need to do here is to forget all that regurgitated NONESENSE about "lowering compression to 9.5 to 1 for pump gas" and get the hell away from these frequently recommended on here "tiny cams" on tight LSA's. You are just shooting yourself in one foot then the other one following all that ridiculously outdated information......IMHO.......Cliff