Engine no wanna run :(

[LTZ C20]

I mean yea it's balanced but not like you get when you do balanced and blueprinted engine.

[rich weyand]

If the Speed Pro pistons are flat, run 91 octane.  If they are dished (Is that what you mean by "stock style pistons"?), then the 87 octane should be fine.  Like I said, test it.  And fill it only half a tank with 87, so you can add 91 and get to 89 if you get knocking.

[LTZ C20]

If you turned the piston upside down and put it on the table, it would rest flush on the table. Without the middle being higher than the edges. So it's flat across the top but with 4 valve reliefs.

[LTZ C20]

I have used 91 in it since the very beginning of this engine.

[rich weyand]

If you turned the piston upside down and put it on the table, it would rest flush on the table. Without the middle being higher than the edges. So it's flat across the top but with 4 valve reliefs.

Use 91 octane, then.  Your compression ratio is higher than I thought.

[LTZ C20]

So I was on the right track anyway.

[rich weyand]

So I was on the right track anyway.

Yup.  And with that higher compression ratio, the large-vacuum-advance distributor with a low base timing is looking smarter and smarter.  Means that the spark will be way back from the detonation wall when you pull hard at low rpms, even with that compression ratio.  Nifty.

[LTZ C20]

Sweeeet. That sounds great to me!! Thanks Rich! I will have to clean up the engine bay, take some good pics and maybe a video and post it up.

[rich weyand]

Put your full setup in that post, please.  Block, pistons, cam, heads, distributor, etc.  With part numbers.  I think you have a pretty sweet build there, and other people will want to know.

[LTZ C20]

Oh don't worry I will. I started one but it kinda got post bones and disappeared. I have to dig out all the paper work and receipts. Go thru and collect all my pictures from the build, organize and sort thru them. Then I will build a complete post. It's going to be everything I have done to the power train. From trans cooler all the way to rear diff. Engine, trans, driveline, axle, cooling system, a/c setup, all that good stuff.

heck, I gonna have to break out the laptop and do it on there cuz that's just to much for my phone and thumbs to handle. Lol