Timken500

I have purchased a 1979 Formula with the 403 Oldsmobile engine and would like to keep the Oldsmobile in it. But if I am going to do this I need a set of 1972 7a heads. I cant drive this car with the 185hp it came with. Please send any Ideas to me would love the help.
I am out of Houston Tx.

2blu442

Please post your city and state, or the nearest large city. I've only got a single 7a but have lots of other castings of small block heads. I've also got several complete engines. I'm located in Oregon and if your on the East Coast it might be worth looking for a set closer to you. John

Eightupman

Just so you are aware you have more options than JUST 7a heads. I understand that you are probably looking at the 7a as having the hardened valve seats, but if you are going to completely go through the heads, hardened seats can be put in any head. You can open your options to the #4 330 head, the #5, #6, #7, or even a worked over pair of #8 heads.

Just remember that just "slapping on" a pair of heads on that 403 may not meet your expectations.

What are your intentions if you don't mind me asking? (perhaps a new thread?)

John

Timken500

Was just thinking about waking up the 403 going after 330 Hp or so. Was thinking of putting on some 1972 7a heads and a nice Edelbrock no emision intake and a mild cam with a 3.42 rear end gear and a mild stall 2200 or so. I am a big time Ford guy. So learning about Oldsmobile power is going to be different. Thanks for the heads up on the other heads I can use.

Eightupman

Well, what DO you know about bolting on different heads and do you know WHY? Just want to make sure you are on the right page as far as "bolt ons" go. And don't want to insult your intellegence because SOME of your Ford knowledge could pose benificial. But as long as you remember its apples and oranges, and NEVER listen to the Chevy buddy concerning Oldsmobiles, you will be OK.

John

2blu442

Just about the center of the US, a good location to ship to. There's also several board members in the Texas/Oklahoma area. If you have time to go to the Oldsmobile Wiki link on this board you can read up on the different early small block heads. As East Coast John said, there are several more good castings to choose from if you plan to rebuild the heads. Here's the link to the wiki site: http://www.oldsmobilewiki.com/index.php/Main_Page

And I should mention there have been some recent threads discussing engine transplants like 350 or 455's to replace 403's in your vintage of Formula and Trans Am body styles. You can do a search to read through those. John

Timken500

Well this is what I know about head replacement. 1st I would benifit from the compression bump. Second I am hoping that using a old non smog head I won't have exhaust running through the intake. 3rd I am hoping the old school heads will Flow air and exhaust better. I saw a set of #4 Olds heads bare on ebay and they want 200 for them with free Shipping. I was worried about them comming on a 330. Does this have smaller intake and exhaust ports?? Also what size valves can I have put in this head??

J-(Chicago)

Biggest valves that I'd run are 2.07 and 1.625.
#2 through #7a will all get you the compression bump and flow nearly the same.....crappily.
#2-#4 will need the push rod holes enlarged a little on the bottom because they were on a 45 degree lifter angle instead of the later 39 degree.
#5-7a have the 39 degree angle.
I must warn you, that ALL of the older small block heads 64-76 will need the head bolt holes remachined, because those 403's came with 1/2" head bolts.
The older motors had 7/16" bolts.

The 403 heads have bigger valves already, but crappy chambers. Depending which way you want to go, you could mill the crap out of your 403 heads .080-.100" to gain compression.
Bolting old heads on alone won't get you 330 HP I don't believe. The valve bowls are all restrictive on every olds head, and need work to perform.

Eightupman

Ok, you are on the right path. That is good to know. Ok, ALL of the heads we are speaking of have the exhaust gas running under the intake, so in any case you will have to block the ports. If you buy a new intake it will come with cast plugs that you gently tap into the head. You can also use an old piece of intake gasket material to block that port as well.

As J mentions there needs to be some mild work done to get these heads to breath better. Removing the A.I.R bump is #1. Its the odd bump that you can feel at the top of the inside of the port. #2 Then you should at the minimum pocket port the valve area. Meaning, make the runner opening the same physical size as the valve seat. Once you take a valve out, you will see that the casting is not a "cylindrical" shape down into the head. Some time and a dremel tool and the right bits will make a nice run, without causing pain in the wallet. Symmetry is the key for all cylinders. #3 is to have the gasket surface milled at least .010-.020 to compensate for a.) the thicker aftermarket headgasket or b.) the aftermarket pistons that will sit lower in the bore than stock. You could also get the block zero decked, but I wouldn't for a mild build.

So for any of the heads mentioned, (minus the machine shop installing hardened seats... that some people choose not to change due to the high nickle content of Olds iron) a little massaging will get you closer to that goal, AND opens up your possibilites for purchase.

and IMHO, $200 shipped for core #4 heads is too much. Bide your time and you should be able to score a set of #5's for that money, or 7's or 7a's cheaper.

John

redoldsman

Here is a set of 7a's in Fort Worth for $75. Price seems right.

http://dallas.craigslist.org/ftw/pts/1517449470.html

Timken500

Sent that guy 3 or 4 emails with my email address he will not respond to me.

StickW31

I have a used set of 7a heads, complete off a running 350 Olds, $150 plus shipping or I have 5, 6 , 8 casting heads if you change your mind, those are $150 a set also plus shipping

PM me if interested

STEve