Hey newbie here. been checking out the site for a while. My question is, has anyone ever used any old 283 power pack heads casting # 896. I have a set lying around and my small block performance book says they have 137cc intake runners and 59 cc combust. chambers. Would it be worth the while to have larger valves installed with hardened exhaust seats. The stock intake valve dia. is 1.72". Im trying to save a little money and use some stuff I already have

 

Chances are, what you have already blows them away. Even a stock 305 comes with 1.84 intake and 1.50 exhaust valves and a larger intake runner. Those heads would kill even an LG4. LOL

 

What is the intake runner size on an LO3?

 

They were a good head in 1957!! In other words JUNK!

 

They are crap... those are not the "power pack" heads, that is one of the names that people used to use to refer to the "double-hump" or "fuelie" heads, which those are not. Yours are 283 2-barrel heads from a truck or Impala or something.

They also don't have accessory bolt holes, so they are incompatible with little details in outr cars like .... alternators.

Keep looking.