I have had this pair of cast iron toplines I have been meaning to put on. I got them bare. Do I need a machine shop to do anything? I have new valves, springs, etc, etc. The instructions say that they are to be milled before installation. Is this true? They look more straight than the heads that I put on there before (came with the car - old 69cc open chamber heads).
Also, will I notice much of a difference with these heads?

You'll need to have the valves lapped to the seats...you can't just assemble them and run them. They shouldn't need milled either, but it would still be a good idea to have your machinist check them for flatness. You'll also have to check the springs installed height.
Oh, and IMO, you REALLY need to get a looser convertor in that thing. At this point it would make more difference than a head swap. Something in the 2600-2800 rpm stall range would do nicely, assuming you have the rear gears to go along with it.

I think the instructions pretty much answered your question. It wouldn't hurt to remove a thou and see what happens.

Not sure why they'd say that though. I just wouldn't have the "peace of mind" knowing that I didn't mill the heads like the instructions said to do.

Have a machinist/engine shop assemble them. Especially if you can find one in your area that has experience with those heads. I think it would be easier and more cost effective for you, assuming you don't have all the head assembly tools.

Also I saw in your post that your not sure of gears you have. Well there's this degree wheel out now for rear end gears. I'm not sure who makes it, but I read about it in a recent Car Craft or Super Chevy. It looks a lot like a cam degree wheel. It will provide you with an inexpenssive way to know what gears you have. Or you can do the speed at a given RPM calculation. That will get you close too. Good luck. graemlins/thumbsup.gif

The instructions say the heads must be milled to change the chamber volume to get the compression ratio you desire. The guides must be sized if they are bare heads.

Lay a straight edge accross the head mounting surface at various angles. If you can slip a 0.007 feeler guage between the head and the straight edge they need to be milled. Less than 0.005 is ideal. You should not be able to slip the feeler guage in anywhere. But make sure you guage is flat. When you get your valves done, the machinist can do this for you.

To figure out the rear gears you don't need anything that's not on the car. Put a chalk mark on the driveshaft and a mark on the tire. Rotate the tire 1 revolution and count the driveshaft revolutions. There's your gear ratio.

a competition valve job.

Originally posted by dnult:
Lay a straight edge accross the head mounting surface at various angles. If you can slip a 0.007 feeler guage between the head and the straight edge they need to be milled. Less than 0.005 is ideal. You should not be able to slip the feeler guage in anywhere. But make sure you guage is flat. When you get your valves done, the machinist can do this for you. thats not the way i do it, nor would i be happy with those tolerances.

You need a straight edge that has been ground flat, not milled.

I put the straight edge across the head, and put an .001 (Read, one thousands) feeler guage under the bar, if i can tug on it, and it wont slide out, then i move to the next position, and i try it on various positions around the chambers, and water holes.

I'm not trying to pick on you, but just letting you know, that i do it differently.

the instructions say to mill them, becuase they use a rough mill cutter, on a steep angle to get them done quickly.