i can't seem to find the specs for my melling cam can you help all i know is the pn# soc9. >>>>> i had the engine in my 78' trans am rebuilt it's an oldsmobile 403, i was looking for a little performance so i had the mechanic bore it .30 over and add a mild cam so he chose this melling cam(soc9), since then i have added an edelbrock performer intake, performer carb 750cfm spred bore,summitt distributor w/50k volt coil,taylor sst 8mm wires, msd 6a,dynomax cyclone headers,dual flowmaster,3:73 gears were installed in the 10bolt limited slip diff. when i have another person in the car or going up slightest hill of a road the car feels like i'm pulling a trailer or somthing,so i'm really happy with the otcome so far, i have a feeling it's due to the cam. but currently i am looking for set of heads from a olds 350 #5 or #6 i think this head swap will help bring out the performance in all the other goodies i've installed already, do you think the current cam is enough or can you suggest a stouter cam without having any vacum issues, the car is street driven  and has yet to see the track and probably won't too often. p.s. to anyone who might read this (lesson learned) if your mechanic can't tell the specs of the cam he chose for your car go with another guy.  

In my opinion probably the limitation you are up against are your heads, but going to small block heads may or may not help you.  If you can find small block heads that have big valves then you might be ok with them. 

I think that the real question is what heads do you have on there now? Are they big block or small block heads?  Idendifier is easy by looking at the lower corners right by the exhaust manifold.  On one end or the other on each head there should be a number or letter plainly visible.  Let me know what it is, we can figure out what you are running, and what you can use to really improve the aspiration of the engine.

Chances are, whatever you are running are smog heads, and I can give you some good choices.  If you are running big block heads, then the sky is the limit for both aluminum and cast iron.

I will be out of town the next two days, but can get back to you as early as Sunday evening.  Talk with you then.

Bowser

yeah i'd have to agree with you on the heads i've read numourous articles about the heads being a problem for this engine, i think they have like around an 86cc size combustion chamberand the heads that i'm currently looking for wich are #5 or #6 castings from a 68' - 70' olds 350 i understand that the best ones were offered with the w30 performance package. but the answer to your questions about wich heads i currently have they are the small block heads. but if you know any other suggestions (heads or other) please let me know and i appreciate your help thanks.  

If you go to #4 heads like off of a '67 330, I believe the chamber drops to 64 cc's.  I will double check that for you tomorrow.  Do you have any idea what your compression ratio is?  Depending on the heads you use, that can do a lot.  You also can find heads with the smaller cc chamber and the large intake valves which would be the best in your case, unless you are already up around 9.5:1 in which case you really don't want much higher.  As for big block heads, there are lots of good choices there.  We can discuss those when you give me what your compression ratio is.  An estimate would be OK.

Bear in mind that the W-30 was a big block 455 engine.  You can use big block heads in place of small block ones with minimum modification.  I have big block heads on my 1967 330 (big valve F heads off of a 1970 W-30) and they work great.  We can talk mods later if that's the way you want to go.

Bowser

the compression orginally is 8.1 so i don;t think that i've done anything to massively improve that if any. maybe i'm looking for the wrong package (w30), supposedly the 350 heads from those years are a direct swap for the 403 heads with the exception of the bolt holes having to be drilled bigger on the 350 heads to ecept the the 403's bolts, are you familiar with this idea? the reason i'm insistant on the 350 is because it's the only swap i've ever read about and all the interanls of the 403 fit in the 350 heads, i have decent valves(1.97 or 1.99 on the intake side) it's my chambers that suck. your 330 suggestion is the 1st time i've heard of it what all is entalied?    

Ok - 8:1 is what is holding you back.  The #4 heads I was telling you about have a 60 cc chamber, and it has about the same size valves that your engine is running now.  At 8:1 that is going to bump you up at least to 9.25 if not more.  You will get better performance and economy (believe it or not).  The head internals on every olds engine from 1965 on will pretty much interchange.  I have a 425 with some other type of stud system I have never seen before, but most are compatable between big and small blocks.  The first year for the 330 (1964) used an older style rail system, but it was only on that one year as far as I know.

The W-30 application is a big block head.  The direct interchange that I am aware of like head for like head would be the W-31 package, which was a production plain jane Cutlass with a serious 350 powering it.  It was a special order and they are rare as hens teeth.  A set of heads off of that special "Ram Rod" engine would work directly on your engine, but good luck finding a pair.  If you do find some - be prepared to shell out some serious buckage.  If they are real, the guy will know it and be asking major buckeroos.

As for the big block heads, there are some real good choices there.  Anything off of a Toronado pre 1970 will be some good flowing heads with big 2.072" intakes.  Many of the 442's (some in '67, mostly '68 and '69) also have the big valves.  These will be "C" heads, and are probably the best bang for your buck.  The adaptation that needs to be done is that your heads and your intake will have to be port matched, because the passages don't directly line up.  If you need help, your local machine shop can probably do it for you.  You take the material mostly off of the intake, but it can be tricky.

Make sure that all water jackets are going to clear and be accomodated as well.  There should be no rub there, but I would check it anyway.

If you find some heads and need some help with ID, let me know.  I have some of that information laying around and might be able to help.  The 330 thing is a slam dunk though.  Those should be the same cam bank angle and fit the same as your current small block heads just like the heads from any 68-70 350.  The #4s I have are going on my sons '72 350, and I don't expect any problems.

Let me know how it goes.  Bowser

     I wouldnt recommend BB heads on a SB. The intake runner volume is to big for a street SBO. Also the only intake that you can port match to the BB heads is the Performer RPM unless you add alot of aluminum to that performer intake. The RPM intake would be a better choice anyway. If your engine builder used modern head gaskets and didnt deck the block (which I am SURE he did these things) and you have stock or even worse stock replacement pistons (these have a .03" shorter compression height) you would have 7.6:1 compression. Now if you go to #5,6 or 7 heads with a gasket thickness of .028 that will only get you to 8.6:1. If you mill the new heads .06 (which is as much as you want to mill Olds heads) that will get you to 9.4:1. But the best thing to do is rebuild the engine right. With the 9.4:1 compression I would suggest a cam with 216/226 on a 112 LDA. This will give you gobs of torque from down low all the way up to 4500-5000rpm. You will love it with 3.42 gears and a 2500 stall.  

I don't believe that big block heads on a small block is an issue.  Speaking from my own personal experiance its actually a very cool swap.  I drive my car daily and it idles perfectly, and now, with the 200-4r I recently rebuilt it cruises 65 mph at 1700 rpm (3.08's out back).  And mine is smaller than his is (mine is 366 cid after boring).  I'm not sure whether a stock or a performer intake can be easily modified to accept big block heads as I've never tried it (I went with the Performer RPM as you stated...great intake), but with a decent machinest I'm sure they could work it out.  

Small block heads would be the easiest...

I have slightly less duration than you mentioned...but mine could stand a little more...and the converter and gears are right on the money...I'd say take those recomendations and run with them!!!

I would agree that it would be nice to redo the engine for a little higher compression, but if I understood all this correctly, you just had it done.  I would agree with the gentlemans statement that the small block head swap would be easier, but to say that the big block heads aren't a good idea - well, his opinion.   I got around the compression ratio issue with the pistons I used, and there was a little shaved off of the heads as well.  With the set up I run, my machinist figured a 9.5:1 (plus or minus) compression ratio - that is without calculating it to the exact detail.  I run a pretty big cam from comp cams (for a small block 330) and it has a very rough idle - but isn't an everyday street car either.  If you want, I can give you the whole engine list - I gave it to CIS.  The engine has been in the car for 3 years without problem. 

Now, by going to a 60 cc head with all other things being equal, you are going to get some better performance.  You can also use like steel shims for your head set instead of thcker no re-torque set.  Even if you can hit the 9:1 range you will be better off. 

Thats my opinion

Bowser 

    The BB heads will work ,but wont be optimum for a mild street SBO. Besides its alot easier to put SB heads on and if your unwilling to rebuild the engine the BB heads wont help much even milled with the compression ratio. A pocket port on the SB heads with have them flowing just as good as the BB heads and will give you higher velocity in the port than the BB heads.  

No - don't think I am disagreeing with you.  When I built my engine, the big block heads were added as a part of the entire build, and we (my machinist and myself) picked the parts rather carefully to give what we wanted.  As you may have noticed, I let everyone know that the 330 I run is not an average engine.  It runs with a very rough idle, and I have had to put in a higher rpm torque converter and do other things to accomodate it. 

Initially I tried the stock converter and two speed transmission and it was a joke.  I couldn't keep it in gear and at an idle without doing the two foot trick.  Now, would I want that for an everyday street car? Probably not, but that's not what I was building for to begin with.

The BB heads on the kids 403 would not be my first choice either.  I was offering it as an option because given other things (such as pistons, etc.) they are an option.  In his case, not a good one with his low compression slugs.  I would go with the 60 cc heads I told him about (they are #4 small block heads).  It should give him an increase in compression ratio (however modest), and the valves in the #4s have the 2" intake.  Now, that's not the biggest that can be found, but will probably be the one that is most likely to be found.  They also will be the 45 degree cam bank angle so there should be no push rod issues there.  All '1967 330s were the 45 degree cam bank angle (as indicated on my cam spec sheet and the 1967 Oldsmobile Chassis Manual).  So going to the #4s should be a safe bet.

Outside of that, I agree.  Rebuild with higher compression pistons, but I really don't think that's an option he wants to take right now.

Bowser

I understand what you are saying Bowser. I didn't have the impression that you were disagreeing, just giving a different perspective.I can tell you know Olds engines very well.

#4 heads have 1.875/1.562 size valves.

Your right.  Book size on the intake valve is 1.875.  My measurement was rough with a caliper right off of the head.  I will look at the build sheet for those heads too because it seems to me that a bunch of the valves had been replaced.  They may have been enlarged, although the guy that sold them to me didn't say anything about it.  They were rebuilt by a NAPA machine shop here in town, and I have the receipt for the work someplace.  If I can find it, maybe that will explain the disparity.

Bowser