What octane can I run with an all iron 10:25 350?

[MrSony]

Converting to E85 is too much of a pain in the *ss.

 

[olds307 and 403]

The Felpro's should put your compression around mid 9 to 1 compression. As long as the factory cam isn't tiny, it should work.

 

[drogg1]

What cam are you going with? A cam with a later Intake Closing Point (ICP) will result in a shorter effective stroke length and lower dynamic compression ratio.

Considering the ~9.7:1 static, a mild cam would probably drop it to ~9:1 dynamic which you can easily run 91 with.

 

[pontiacgp]

Those are the factory specs of a 1970 350-4 SP code motor. I plugged in the specs to the motor into a compression calculator, and got 9.7:1 static, and a bit more than 8 dynamic.

have you seen the engine yet to make sure the block is stamped SP and to see if the heads are original. If you have seen the engine have you done a leak down test and a compression test

 

[MrSony]

have you seen the engine yet to make sure the block is stamped SP and to see if the heads are original. If you have seen the engine have you done a leak down test and a compression test

Yep, and nope and nope. I'm tearing it down anyway for inspection and a re gasket.

 

[lilbowtie]

Shouldn't have a problem on premium - as Motorhead said watch your timing, if you get pinging it will be @ low load high vaccuum light acceleration, adjust accordingly

 

[pontiacgp]

Yep, and nope and nope. I'm tearing it down anyway for inspection and a re gasket.

if you're tearing it down might was well throw in new rings, bearings, timing gears and chain.....etc

 

[MrSony]

if you're tearing it down might was well throw in new rings, bearings, timing gears and chain.....etc

Yep.