I'm using speed pro flat top with the four valve reliefs

 

You need to know the cc's of the valve reliefs. Other key issue will be the cc's of the stock heads, having been cut as much as yours are. I would have someone cc the heads, so you can make an accurate calculation of static compression ratio (SCR). Then you need the cam card for your cam, showing the valve timing events, so you can calculate dynamic compression ratio (DCR). How high you can go on compression ratio vs. fuel octane will be determined by DCR.

Compression Ratio Calculator - Wallace Racing

Wallace Racing: Dynamic Compression Ratio Calculator

 

can you tell me the difference between 010 under bearings and 010 over bearings? All my rod and mains say 010 and it was a crank kit from autozone that came with the bearings from previous owner 150 miles ago, so would that be 010 under? I had crank polished and machinest said go back with the 010 under would that be correct?

 

What 10-under means is that the crankshaft journals have been machined to a diameter that is 0.010" smaller diameter than standard. This then requires a bearing set that is thicker to give the correct oil clearance. Your machinist is, obviously, correct...

 

Ok looked up the pistons and they are 7cc these are pretty much factory 30 over replacement pistons.
The stroke is factory
The heads have had 0.025 taken off
As far as cam card not sure what that is but here's the specs of the cam
08-432-8 - Xtreme Energy?
The head gasket I'm going to use is 1074 which are 0.39 I believe.
Block been bored 30 over
Can u help me calculate my compression with what I gave you I tried and got 11:2 not sure if that's right

 

You use the site I linked (or any other of your choice) to calculate the static and dynamic compression ratios.

As I already noted, you need the cc's of the head combustion chambers. Do you have that? That would be the only way you could do the calculation you just did. Since the head is domed, as you cut more off the surface, the volume of combustion chamber removed per 0.001" cut is not a uniform number. The heads really need to be cc'd by a shop.

You also need the deck height.

If you are uncomfortable with making the calculations, it would probably be a good idea to enlist the assistance of a reliable shop, in order to insure the correct selection of each and every component in the build.

 

This is an example of needing to coordinate all the correct parts. That cam spec indicates:

 

Yea I know about the cam it's not lt1 specific but there's few guys running them in lt1s it's been in this motor for over 1 1/2 if you look on this sight there's few guys running them the only difference with this cam is the whole at the end and dowl pin in which this one works on my vented opti system. Trust me when I pulled the cam and ran the numbers and seen that it said not for lt1, and I thought same thing as you, but I did my homework and searched to see if it works and from what I've seen is that it does and has on others and this motor

 

Well stock is 54 isn't there a way to calculate the cc from the decking? Seem I seen somewhere that every 0.05 taken off is 0.6 cc drop something like that, and block deck is stock.

 

https://www.camaroz28.com/forums/lt1...ut-cam-127996/
Check this post out mainly 2nd page last post then the third page

 

The way I read that thread, it concludes that while the cam has the 08-432-8 specs, it was ground on an LT1/LT4 core. Is that in fact what you have?

Part of the confusion in trying to help you is not knowing the status of the build. I originally assumed you were putting milled heads on an existing engine - you told me I was wrong, you hadn't built the engine. So I figured you were assembling parts, to build the engine. But now I'm wrong again, since you in fact are trying to rework an existing engine.

I'll drop out, because I'm way too confused at what you are trying to do, and obviously not able to offer you the help you need.

 

Don't meen to sound confusing I'm sorry on that. The cam was in the car when I bought it it had blew head gasket and yes I'm building it and I have just got block and heads back from machine shop I had them check clean and bore the block, and they milled they milled the heads along with valve job. I think where the confusion was is where I said I'm building it you prob thought I picked the cam, but infact it was ran in the car when I bought it. It's the same exact cam as the one in that post the 110 lobe sep too. I thank you very much for being there to help out and hope this clears it up a little lol

 

And nj is hell haha I was born and raised in Delaware

 

spcquinn

you should go to the machine shop that did the heads & block. Take your pistons in also and have them calculate the compression ratio (11.5 +/-) and spec a head gasket thickness to get that. The Impala iron head gasket is .026 IIRC and the FelPro 1074 is .039. One or the other should work...but you really want to confirm