How to make #8 heads work. Waist of time?

[ForMySon]

I'm still in the planning stages for my 82 Cutlass. Getting ready to pull the motor 395558 2, not sure of year, but it does have #8 heads 411 929 or 829(can't remember numbers off the top of my head).

Can these heads be worked to flow well for a 350hp build or will I be waisting my time and money?

What will need to be done to make them work?
and
about how much $$$$ if I paid someone?
or/vs.
doing the work myself (i'm new to working on engines but i may attempt the work myself)
or/vs
buying other junkyard heads?

I just need all the various options so I can decide how much I want to spend. I'm thinking about doing the work myself and buying what ever tools I can. This will give me some experience something to do during the day. I know they'll need to be ported and (milled down?) to decrease cc and may need larger valves.

 

[mheath717]

Well I'm glad it didn't just happen to me. I also bought a '68 - '70 motor that I thought was going to be a great deal. I had the same exact block numbers as the one you got. But somehow I got number eight heads on mine. :x I pulled the numbers on the heads and I found they were from like a '76 low compression motor.

Curious to see if you find out anything good you can do with them.

 

[Kennybill]

Don't waste your $$$ and time on #8 heads. Find a set of 5/6/7 heads. Where r u located?

 

[ForMySon]

Don't waste your $$$ and time on #8 heads. Find a set of 5/6/7 heads. Where r u located?

Tyler, Texas; East of Dallas by 2 hours. How much can I expect to pay? Are they easily found in a junkyard/possible prices to pull myself?

Curious to see if you find out anything good you can do with them.

I've spent numerous hours reading all available resources on this website and I think I found where one could do enough work on them to get them flowing well; can't remember where, how well they would flow, and if cost effectivness was declared. (Wow! Did I use proper grammer to structure that big sentence?)...lol

Very useful information for someone who is OCD and wants (No! has) to know all variables before digging in. I just can't decide until I know, else my OCD will make me regret it...lol...this is my fun toy, after all.

 

[FE3X CLONE]

Any Olds head can be made to flow as well as any other Olds head with enough porting. It just depends on how much you value your time vs buying a set of better flowing heads from the get go.

Something else to consider is that the #8 heads have huge 80cc combustion chambers which means you'll either need to shave them down or buy high compression pistons to get any decent compression out of the engine.

 

[mheath717]

My main concern was the low compression ratio the #8 heads along with my dish top pistons make. But at the moment, this is sadly my daily driver. Once I get a Silverado, I will begin my search for some #5 heads, and a performer intake manifold.

 

[ForMySon]

Ok, sad but true, not much help here. So, I did a search for used olds heads #5, and couldn't find anything with a simple few searches.

So, still don't know prices I might expect to pay.

My next step will be to find out how much head work cost for the #8.
I'm guessing nobody here wants to impart a general cost for this: (from Olds FAQ)
"If you are really concerned with maximizing flow, just follow the standard porting techniques for Olds heads. Remove A.I.R. bump, teardrop the valve guide, port-match the intake and exhaust ports and manifolds."

If this site is not suited for such as I, someone man up and say it.

 

[Peter]

I personally bought a set of #5 heads and i got them for 200 bucks shipped to my door. I leak tested them and they needed a typical valve job,to be planed, seals and everything else that goes along with a typical head/valve job. That is roughly going to run about 400 dollars. I am not doing any porting or polish or any of that good stuff mainly because i am not running headers so it probably wouldn't make too much difference. I going to be using these 5 heads along with an older OL4B intake and a Lunati Voodoo cam on my 77 block and will hopefully be making 300 hp or more.

 

[CHRIS.O]

It depends on how much the heads need work now, if they need a full rebuild and porting then you might as well throw them in the garbage. You would be looking an easy 1k bucks for full rebuild and port work to get them to flow well and cut them down to a smaller chamber. Port work is pretty damn expensive. You should be able to find some core 5/6/7 heads for around 200 dollars for the pair. You can check out junkyards I am sure there are still some old Oldsmobiles out there waiting to be picked through.

 

[DoubleV]

I think the #8 head has it's place depending on your application and goals. For example, if you're doing a full engine rebuild and want to go with a cheap set of forged flat top pistons, the #8's would be a good choice if you're looking for a mild 9:1 or so CR which will also give you ideal quench using cheap Felpro head gaskets. So the big combustion chamber in this case is a benefit to you, not a liability.

The #8 has extra material behind the exhaust valve that if cut out will flow just as good as the earlier heads. The #8's also have bigger exhaust valves than the earlier heads too if I'm not mistaken.

I won't touch on the cost, because it can vary so much. Just remember, quality costs. Don't think that if 'Joe Blow the Chevy guy' down the street says he'll do everything you want done for only $300 you're gonna get back a quality set of heads. If you want them done right, expect to pay or do it yourself IF you know what you're doing.