does anyone have a set of oldsmobile #5A cylinder heads up for grabs? how much?  

I got some #5s off of a 330, but I got plans for them.  If I end up not using them I will drop you a line. They are rebuilt and ready to go. If in my gaggle of crap I run across some that aren't rebuilt but good cores you you still be interested?

Bowser    

Are you looking for a set of #5 or #5A heads?  If its 5A you should be able to go to a salvage yard and find them out of an early 80's cutlass or delta 88.

If you are looking for a set of #5 heads, you might want to list a general location.  Heads aren't cheap to ship.  I have a set of #5 heads from a 68 350.  Unfortunately I don't have too much reason to sell them, they have not been rebuilt, and they are the small valve heads (not W-31).  I'd probably ask more than they are worth.

I've got a set of #7A heads I'd love to get rid of...but those are worthless for any application...and I'm not mean enough to even try to sell them.  

are the #7A's really that much worse than the #5A heads? cause i got a nice cam in my 307 it .444/.434lifr .212/.206 dur and 112* lobe separation. no headers but i do have a 2" true dual exhaust. would i beneifit from a set of 5A heads and if so would it be worth the money/time?  

Really the answer to your question is yes. #7 heads off of a '72 350 are the reason why the '72 is a low compression engine. If you are looking for a performance increase through the use of heads, then you need to use the big valve small combustion chamber heads like say a set of #5s that have been modified to take the larger valves. God bless you if you actually scored a set of W-31 heads, but it aint too likely.  If you found a set, the guy would know what he had and the price would not be pretty.  If you find a set of #5s and rebuild them, between the compression boost and your cam, you will notice a difference.

Now, #7s have their place.  If you are going to put in high compression slugs and do some porting work, #7s can give some real good flow stats. The catch is to find someone who does that kind of work.  When paired with a complete rebuild, they aren't that bad of a choice.  But if you are looking for even modest performance gains, then a head with a smaller combustion chamber is a better way to go.

Bowser    

well i have 9:1 comp on my 307 and the builder said that he did a 3 angle valve job.. if he ported them i dunno but i would hate to go through the effort of swapping head just to find out that i am going to get the same performance out off my "built" 7A's and Stock 5A's  

If you are refering to the 7A heads from 72, you are fine (the A is kinda like a subscript).  If you are referring to the 7A head from the 80's, you've got extremely tiny ports.  Problem is, in order to gain any benifit from replacing those heads, you'd have to replace the intake for sure...and possibly the exhaust manifolds.  The later 307's with 7A heads supposedly had a tubular exhaust manifold that doesn't flow.  My 307 has the older style manifolds that will work with any head, you might be in the same situation.  The intake had smaller passages to match up with the smaller ports...no flow.  

If he ported them, he wasted time and money.  I may go back home towards the end of the month...I'll try to take some pictures of the ports on the 7A heads, and the 5 heads on my 68 350.  You'll be amazed at the difference.  You would be better off with a better head...but then again, a 307 isn't usually a good performance candidate.  If you insist on keeping it though, I'd personally recommend a head and intake swap...shouldn't be too expensive to get a set out of a salvage yard.  

I echo what you are saying CIS - what I didn't know was that there was a difference between early and late 7A heads. You learn something new everyday.  To tell you the truth I have never cracked open a 307 or a 403 for that matter.  I have pretty much stuck with what I know, and that's the earlier stuff like the 394, 330, 350, 400, 425, and 455.  

I really think that #5 heads is the way he wants to go.  If he is running 9:1 already, the compression boost may make things hard for getting gas that won't pre-detonate esp. in hot weather.  I agree completely that the older heads (say from '67 or '68) will have good flow even with small valves.

I also agree with the statement that a 307 isn't the best engine to work on. When he gets ready to do a rebuild he should go with a older 350 block for the miriad of reasons that we all know about.  You can still pick up a 350s for reasonable, so between the weaker main construction of the 307 and lower nickel content of the iron, there is no reason not to go with a 350.

My two bits for the day.  Bowser  

When I was taking the 307 out of my Delta 88 to make room for the 425, I just ran the numbers on it, curious to see what it had.  It was a good motor, 180k miles and never a valve cover off.  But after checking it out, it had the 7A heads, and the intake to match.  After I pulled the exhaust manifolds I saw how puny the exhaust ports are, and was seriously stunned.  That explains the good mileage on the highway...2.50 rear gears, .67 overdrive, lockup converter, tall tires, tiny ports...it also explains the anemic acceleration.

I agree that pretty much any head from the late 60's, or even some from the early 70's would be best.  However, if he wants to keep emissions equipment, he'll be stuck with the 5A heads.  The 307's had the AIR injection tubes machined into the heads...not exhaust manifolds like Chevy.  I was actually planning to keep some of the emissions equipment when I swapped in the 425, but after learning about the heads, I decided just to scrap everything except a catalytic converter (hey I kinda like the enviroment... ).

I'd actually like to work on a 394...they seem like neat engines.  Right now I've got more motors than cars to put them in...so the last thing I need is another one.  I've still got a 68 350 lying around...I'd like to use it for the Cutlass when its motor dies...if it dies.    

Eventually I will need to rebuild a 394 for my convertible.  It's the '61 Dynamic 88 I told you about.  I can't justify doing it right now because it's still running good. At 109,000 miles it should last for awhile. It does have quite a bit of blow-by, but I keep the oil religiously changed to keep from washing out the internals. I don't drive that thing more than 200 miles per year, so the rings may well be stuck.  If it were taken on a trip or something they could shake loose.  I have a spare engine for it in the basement out of a Super 88 with the factory 4 bbl manifold. I will need to go through that one too as the dude I bought it from didn't preserve it correctly and it seized up on me. It really doesn't matter.  Even if it were a runner I would break it down for a good cleaning and once over.  I also have 2 slim jim trannys sitting around for it since they are becoming almost impossible to find.  One came with the engine, the other one I bought from a guy I know in Oregon.  It is out of a '64 98 which is the last year they made those.  According to an old time transmission guy I talked to, 1964 was the best year also for those units.

So don't feel bad about having stuff lying around.  When you are working with old iron, you almost have to.  I especially have critical spare parts lying around for the '61, because it could take you a month of Sundays just finding a fuel pump for one of those.

This weekend is going to be nice, and I plan to play around some.  If I take some of the nice cars out in the open I will attempt to post some pictures.

Later - Bowser    

As promised here are the pics comparing the 7A heads with a traditional Muscle era head...


7A head...look close and you'll see its not rectangular...its round.  Pay special attention to the center ports.

These are the better heads.  As you can see they are quite a bit larger than the 7A heads.

Note: the tape measure is only there to provide a visual reference...its not measuring anything.  

i happened to just like out. i bought a 84 Buick wagon for it power windows, seats, and fenders (which don't match my chevy exact) for $100. when i drove it home i noticed that it ran strong, really strong. so i took a peek at the heads and luck me there 5A's so now I can slap them on my 307, replacing the 7A's and help that nice cam i have breath better  Also i can final put the headers on and but a performance intake  

Awesome...good find  

Hey Squareback - Out of rank curiosity, if that engine is running strong or "really strong" as you put it and it has 7A heads, what is the block casting number off of the engine?  You may have got a car with a replacement engine out of an older car - or it may be a 350.  Wouldn't that be a score?  Maybe you aren't interested but if you give me the engine code (number is located in that little valley between the intake and timing cover).  Wipe away the gunk and tell me what it is and we can see if it's another 307, or something a little bigger.  If it's a 350 or a 403 or even something better, then you may have some real fun choices to make.  The heads are great, but you may be sitting on a gold mine.  

First, lets see what ya got.  Bowser    

I'll have to check that out tonight