I was planning on taking off my heads and porting and polishing them. Does anyone see any problems with removing the heads from my 305 with 80,000 on them and re installing them with a new head gasket. (Do you think that I would have to have them milled flat ?) I am on a tight budget and will leave them in place if i might have to have them milled.

Any one with any experience with this?

Suggestions..

 

Just make sure to get new head bolts, too.

 

You'll only know for sure if the heads are going to require a
cleanup cut to straighten them out once you remove them.
Consider this thou. If you want to see a significant improvement in head flow (horsepower), you will want to upgrade the valve size from 1.84 to 1.94" while you're at it. Just porting this head without going with the bigger valve will only get you half way there, if that.. If your going to use a larger cam then stock then bumping up the compression ratio a little (shaving the heads) will be really be a step in the right direction anyways. (within reason {octane})
If your replacement head gasket is thicker than the stock one then you'd want to shave the head a little to retain the compression ratio.
If your heads are not leaking now and you've never overheated the motor then they are likely ok.
To get a successfull outcome ( horsepower gain) you want to combine all of the mods togther. (head porting, larger valves,
camshaft duration and lift and compression ratio)
Hey!, its only money, you'll get more.....:sillylol:

 

You won't know if they're OK until you pull them.

You need to check the deck and heads for warping. Lay a machinist's straight edge on each of them and slide a feeler guage under there. If there's any more than .005" of clearance on either the deck or the heads then you need to have both surfaced.

I've seen some as much as .005" on the deck and .003" on the head and they were fine with a .039" head gasket. If you were to use a embossed .020" or thinner gasket, then they would both need to be flat, and I mean FLAT!!!!!

You should also have them checked for cracks while you got them apart, and check the valve guide clearance also.

OR you can take them to a machine shop and have them check all this for you. Just tell them you're on a budget and only want the absolute minimum done to them ONLY if they need it.

I don't recommend skimping like this, but if you go the ants in your pants, then all I can do is point the way for ya.