Compression, HELP!

[werd35]

I am building a 351w for my mustang, the block is bored 30 over and it is going to have stock crank, stock rods, and gt40p heads (has 58cc chambers) , and i am planning on running e85 which i heard has around 105 octane. What compression ratio/pistons should i be looking for?

 

[Rick 91GT]

If your going to run NA I would put as much as you can, 10.5:1 is safe you'll need a 10cc dish to get around there... I get 10.571:1 on my software using a .040" headgasket, 4.03 bore, 3.5 stroke, 58cc chamber

 

[werd35]

thanks, you know what they say, fix it til its broke. going to twist some things more than likely

 

[SMOKEDYA]

If there is no part number or with the pistons in the block still how can i tell the compression of them? Mine are dished and are stamped on top 40. So i assume mine are 40 over? My 351 is a rebuild with low miles but thats all i know about the block.peace








john

 

[werd35]

im getting new ones and there are compression charts.......