What's the difference in porting and milling heads?
 

I found a set of milled 243's on craigslist for $300. I'm interested, but what exactly IS milling? Is it better than porting?

Milling is shaving the whole bottom where the head meets the deck of the block. It lowers the compression adding a lol power. Porting heads is the inside runners and chambers getting cleaned and smoothend for better air flow

so if heads are milled, will they fit right on to my block, or do i need to do something else?

Also, is milling better than porting then?

I would be careful and ask what they are milled to. You could run into PTV problems.

milling will yeild some hp but porting i think will get you more. and yes they will fit fine...milling trues the surface area too.

oh yea^^^ if you go with any aftermarket cam you have to watch your PTV pistion to valve clearance due to the heads being milled.

That's what i'm worried about...

ok, it says they were milled to 59cc

i'll have a comp 228/230 .571/.573 112lsa cam in there.
will that work?

I'm sure it was just a typo, but milling raises your compression.

your going to need to get them checked...you can do a play-doh job on it...put the heads on with two small strips of play-doh over the piston where the valves would hit and turn the motor over...thats the gettho way...

^^^woops my bad. im buildin a turbo car so the last few weeks for me everything is about lowering my compression...lol sorry

there's also a guy selling ported and milled 853's for the same price.

he says they were milled .015 and ported to add 50cfm as proven on the superflow 600 flow bench

853s are kind of junk...there the second worse head you can get. id shoot for some 243s or 799s them in stock form are way better then 806-853-241s...