young olds

I had a set of c heads in a machine shop to get cleaned up and milled. started taking them apart yesterday to fill the exhaust crossover and noticed i didnt get a valve job and some of the guides seem loose. So I was checking out the rest of the heads and I mic'd the head thickness from the valve cover surface to the block mating surface. One head came out approx. 3.820 on both sides and approx. 2.155 at the bolt surface by the c. The other head came out approx. 3.815 on one side and 3.800 on the other and approx. 2.145 from bolt surface by the c. Im wondering how that compares to stock, how much has been cut and approximately what cc chambers I have. And is the differences enough to care or is the tolerance close enough from head to head. also is there any way to determine at home if I need new guides?

Smitty275

Those heads have been cut approximately .060 and the chambers will be in the 70cc neighborhood. If you just wanted cleaned and milled that is what they did. You have to tell them exactly what you want done. If you have a dial indicator you can put that on the valve stem and wiggle the stem to see how much it moves to asses the guides.

young olds

I told them I wanted a valve job and guides if needed. I do not believe they even took the rocker arms off. I'm not really concerned about what they didn't do, I was just concerned about the cut and the unevenness on one head/ difference between both heads

young olds

Thanks for your reply though

67 Cutlass Freak

young olds, if you have some extra time you should read through this thread-


https://classicoldsmobile.com/forums...echniques.html


I know it's real long, but it's loaded with technical information that I believe will help you.
Concerning your heads, if you paid for cleaning, valve job, milling, that should all be itemized on your receipt from the machine shop. Did they install new seals at least? How could they have cleaned it thoroughly without removing the rockers or valves?
To check the guides open the valve flush with the head surface, wiggle it back and forth. I don't know of a spec, but if some feel looser than others, it will need guides. If it does need guides, those should be done before the valve job. If you're going to do any port work, filling, or welding, I highly recommend you do that before the valve job. The thread I posted a link to has a wealth of information that will give you the knowledge to be better informed about choosing a good machine shop that is well versed in Oldsmobiles. If there's anything I can do to help, feel free to PM me. Smitty is a good guy to work with and has a wealth of knowledge.

young olds

I've kinda been keeping up with that thread. I plan to do a little bowl work and I had the exhaust surface milled flush. Should I take the heads somewhere and have them cut so they are even or is the variance close enough to not worry? I did go back and look at my receipt and they didn't charge me for a valve job or guides, though I did ask for it. If the variance is tolerable then I'll continue with filling the crossovers and bowl work then look into a valve job and guides.

67 Cutlass Freak

I would be careful with that milling of the exhaust surface. A friend of mine did that and had header clearance e issues afterward.
I don't think the variance will make any difference. You want to be careful about milling too much. You might already have to mill your intake to get it to line up right. I hate to do that because it decreases the value of the intake. You will pretty much marry it to your heads. If you try to sell it, after milling, nobody will want it. If you want to upgrade to a different intake, you will have to mill it to line up properly with your heads. You may want to look for another set of heads that don't need guides. We went through this with J(Chicago)'s heads. The guides are $150, install $150, new stainless steel valves and seals $150, valve job $275. Now we're up to $725. I hate to be a neggo eggo and sound like Captjim, but we're approaching the cost of the ProComps. Good "C" casting cores are readily available so keep that in mind. The key is to find them local to save on shipping.

young olds

I had a set of c heads done: clean up, surface, guides, and valve job for $400 a few years ago. I would assume he would charge me the same price. The exhaust surface is already milled so i will deal with the intake fit when i get that far. I figured about a 3cc difference in cc but if it wont matter ill forget about it.

67 Cutlass Freak

That is really cheap. I couldn't hardly buy all the parts for $400 and I thought I was getting a pretty good deal. I question what valves your machinist uses and is he doing full bronze guides or inserts? I really love your project. The older cars are really starting to grow on me. I must be getting old. When I was a young punk these Olds relics were old man cars in my mind. Now they're cool. Go figure. I think you should build your own headers. I did, and it wasn't too hard. I got the flanges from BTR and modified them a little. then I got the collectors and some 2 1/8" J tubes and tacked them together. I had a pro welder tig them up. Saved a lot of money. A custom set of headers will set you back $1500- $2000 unless you know someone. If you're game I could walk you through it. Here's my junk-

young olds

I believe just inserts and he used the stock valves. Thanks for the interest in my project, just got it lifted up and did some measuring for the backhalf. As far as headers i was going to buy a few used sets and chop and modify to make it work. but ill be sure to get ahold of you for any insights. thanks