Via3d

for #3 heads cast number 339417 what is necessary to do to put on a .403 ?

Mondello publication says it is a 39 degree bank angle like the .403 so it should be a bolt on right with no mods right?

Is anything else necessary?

Should I also put this 330 forged crank in the .403? Is any other mods absolute necessary if I do.

Out of curiosity, what is the max bore the 330's can take? Weren't these blocks used to make the 350's?

2blu442

Welcome to the site! You'll need to drill the head bolt holes larger. The 403 used 1/2" head bolts but the 330 used 7/16".

The 330 crankshaft is forged steel and the 403 is cast iron. If your going through the engine changing over to a 330 crank would be an upgrade. You'll also need to use the 330 flexplate as the bolt pattern is different where it attaches to the crankshaft. And you'll want to use the 330 harmonic balancer.

Adding early heads and the 330 crankshaft are common upgrades to the 403.

John

olds 307 and 403

One dowel also needs enlarged as well. Even if it is the 45 degree bank angle, the pushrods holes might need reamed. Also 2" or 2.07" intake and a 1.625" exhaust valve with the bowls opened is a good upgrade.

Via3d

Whew! Sounds like the #3 heads are much more trouble than I realized.... LOL.... easy on me now... noob here.

The heads are 45 degree exhaust valve on the#3 heads, that is only difference I see (besides bolt hole size)... is the cause for the "pushrods might need reemed". What would determone this needing to be done?

Opening the bowls, so more machine work...

And lastly what dowel needs to be enlarged?

Is installing the 330 crank an upgrade just for durability?

olds 307 and 403

One dowel on each head to 5/16", quick and easy. I meant the push rod holes, they might be OK. The larger valves and bowl work with better springs are optional.

Via3d

Choosing a head:
Any SBO stock head W-31 5,6, or 7 etc.
What is expected price range for stock heads ? I have seen $250-400 suggested
A. Should one polish/hone the 2"/1.625" valve seats (W-31) anyways due to mild wear or pitting? [/i] (Could this cause possible valve sink in operation )

#3 head
A. valve seats cut for larger 2.00"/1.625" valves
B possibly need push rod holes larger?


Allelse being equal in consideration:
- bolt hole sizing larger for all the either of the heads #4 thru #7
- Machine decking
- 3 angle seat valve are optional for either

-------------------------
#3 are rated low still @ 66 cc

--->>> I cant find any data that says #5's ports are bigger... several wise Olds senior mechanics say 5's flow best.... I wish I could find specs

Also, do either of the heads match to stock intake ? Would either work with the edelbrock performer intake ? is 3711 the correct one in order keep the shaker? ....

joe_padavano

I'll ask my favorite question again. Would you put 330 heads on an big block Olds 400 motor? The 403 moves the same amount of air as the 400. Get BBO heads, port a 7111 intake to match, and don't look back.

Via3d

Joe I have enjoyed your posts. Obviously your a seasoned Olds enthusiast, so I listen to everything you have to say.

I am just a street rider... not a dragster.

Will the 7111 intake fit under a T/A shaker?

BBO Heads

• From what I see most BBO heads are 79 or 80cc... (So improvement over the 403 heads is 3 to 4cc, negligible right?)
• Already have the larger 2" or 2.07" intake valve in them. similiar to the .403 (So improvement here is negligible right?)
• The exhaust valve is larger than SBO's and the .403 @ 1.625" ( Does this make a significant improvement ? )
• I am guessing bolt holes are probably correct already? not if circa '76 I found....

I will search for your posts regarding heads to try and understand the rationale going to BBO heads....

Heck smaller head chambers create more compression.... what makes the 4a so large?
I also found the NHRA stock blueprint spec to be legal race ready (on the 4a head) is 71.69cc !?!

joe_padavano

If this is going into a T/A with a shaker, you have few options. It would be in your best interest to tell us that up front. No, the 7111 will not fit under the shaker. You MIGHT be able to use an OL4B to mate to the BBO heads, and SOME factory iron SBO intakes might have enough meat to be ported, but you're pretty limited here.

You can easily put the 2.070/1.625 valves into any SBO head. The BBO ports are larger, however, so that is where the improvement comes. Yes, BBO heads have 80-ish CC chambers. With flattop pistons, you get a reasonable street CR.

oldsmobiledave

FYI


#1 & #2 & #3 heads are all from 45 deg bank angle engines.


#4 heads are from 39 deg bank angle engines. So are #5,6,7,7a, 8.

joe_padavano

The only difference is the pushrod hole. Mock up the engine, check pushrod clearance in the heads, open the hole slightly with a drill if needed.

Via3d

oldsmobiledave,
There are technical references that show the 330 engines had both 45degree and 39 degree...
The mondello tech guide is one of them....
It states for cast # 394417 330 engine, it is a 39degree lifter angle....

oldsmobiledave

64-66 are all 45 deg no exceptions.

67 are primarily 39 deg. I recall some discussion on here years ago where a member claimed that he had seen a few 45 deg 67 330s.

Via3d

I do not mean to question you oldsmobileDave, me being a noob and all. But I have done some homework I think on this one...

Head casting 389394 (code3) was a '66 330 F85 ( I have seen these heads and it came from a 394417 330 block)
the SAME Head casting 389394 (codeB) came on the '65 .425 (irrigation)
any significant difference between the two same cast heads? I am thinking no.

The J. Mondello technical manual and AHPS and olds442 source info are all very clear that the:
- 1964-1966 330 cast # 381917 code1 or 1A is a 45degree lifter angle
- 1964-1967 330 cast # 394417 code2 is a 30degree lifter angle

Thus the # 3 heads I have seen are from a 39degree 330 engine.
Now if someone would humor me, and tell the best way to measure this for accuracy I will go verify.

the #3 and #4 heads are practically the same head cc flow
both the #3 & #4 heads = 60cc per ref. olds442 oldsfaq/ofhed
both the #3 & #4 heads = 60cc per ref. NHRA specs rating/allowance
Mondello technical manual: #3 at 65cc and #4 at 64cc

--> The calculation of 60cc heads (#3 and #4) equates to 10:1 compression on a .403.... !!!

yes yes there are production variances in all heads and even cylinder to cylincer... this is just the baselines quoted

Reference(s) further indicate the # 3 heads came only on the cast # 39degree engine...
#1, #1A, #2 heads are the 330 45 degree lifter engines.

Joe P. cautions pushrod holes may need porting, but I am thinking if from a 39degree lifter bank engine, maybe not.

All references I see in forums indicate any of these heads are practically the same heads and bolt on.
So if the 330 block, w/ the #3 heads is verifiable 39 degrees then they seem to be just as savvy as the beloved #4's

Not sure what more would need to be done to mount these heads on a .403 other than bolt size ream, and maybe smooth port and decking it.
Just mounting would seem plenty like much more getty-up without going to larger valves.
As for ripple effect elsewhere on the .403 buildup??? whole other topic.....

joe_padavano

Well, if heads from a motor with a 39 deg lifter bank angle are going onto a motor with a 39 degree lifter bank angle, then yeah, the pushrod holes are fine. My point was that IF there was any question if the heads were from a 45 deg motor, it is very easy to mock up the assembly, check pushrod clearance, and open the holes in the head if needed.

FYI, Joe P also cautions that NONE Of those sources you have cited are factory source material and ALL of them have documented errors. Cite them with caution...

OLDSter Ralph

NHRA specs are from info supplied by engine manufacturer. 60cc was the MINIMUM combustion chamber volume to be "legal configuration" in stock classes. In actual manufacturing practice, the combustion chamber volume was more, which lowered compression ratio, and therefore horsepower.
Not sure where J. Mondello's numbers came from. But I would expect the heads from the engine manufacturer to be several cc's larger than 60 cc's. Valve grinding/valve seat rework will also increase cc's and lower actual compression ratio.

joe_padavano

^^^THIS, exactly. The as-cast chamber volumes on Olds heads will ALWAYS be larger than the NHRA blueprint specs, and probably varied +/- a couple of CC over the production run. Variability in the exact shape of the sand mold, the amount of metal removed in machining the valve seats, and the amount of metal removed in milling the deck surface of the head all contribute to this variability. If the heads have ever had a valve job in the last half century, then all bets are off. This is another example of why I say that agonizing over which head is best is a complete waste of time. These types of manufacturing variabilities also apply to port sizes and flow. NONE of the published port flow numbers are based on a large enough sample size to be statistically valid.

OLDSter Ralph

Joe, correct ! That was what I was trying convey. The OP was computing a compression ratio based on the 60cc NHRA combustion chamber volume.....which is most likely not "as manufactured" or present on subject heads now.

lemoldsnut

I get the original question was about #3 330 heads. What about #4 330 heads? It is my understanding, (please correct me if I am mislead) that #4 heads are basically the same as #5 and #6 heads. If so why not use any of them?

Larry

joe_padavano

And even as-manufactured have variations in chamber volume from one cylinder to the next. This is why you blueprint an engine and CC the heads as part of that blueprinting.

OLDSter Ralph

Joe, Yes to blueprinting and figuring actual compression ratio's. Nice shots of a burette and how its used.

Via3d

Yes Joe I concur the sources are have some errors. And yes I understood and appreciate the caution of the 39 vs 45 degree lifter banks.
oldster Ralph, I understand the NHRA are the rule limitations allowable to be considered stock/superstock.

I may have not expressed my points very clear, for that I apologize.

-I was discounting that all #3's are absolutely from 45degree bank engines. Simply not accurate.
-As far as differences in the #3 and #4 heads.... they are subtle, essentially the same.
-I found it interesting the '65 .425 head is the same cast head for the '66 330 (39 degree bank version).

People, the technical data in reference material are baselines. indeed there will be variances. Tolerances work both ways plus/minus... sure with heads more often higher cc than advertised.
When you have multiple consistent technical material stating that certain year heads are 60cc versus other years at 68cc versus others at 80cc....well there is an obvious difference somewhere then right? (rhetorical) .

Matter of fact - the .403 heads are considered stock NHRA at 72cc's, not 83cc ! It was derived from mfg published material and tear downs that indicated tolerances were seen that low. I am curious about this, why change heads at all then, going through the expense for alternate heads, if you can achieve nearly 10cc less in the 4A head?
---The answer I can predict: cheaper to buy a bolt-on older head than to machine the 4A head ?!? Ironic how the majority of time someone mentions about putting an older head on a 403.... then every tom, dick, and harry says you should machine it (deck it, 3 angle valve job, put in bigger valves, smooth ports, etc)..... Full circle with the point.... what the goal cost or performance or a happy median ?

I like Joe's assertion and starting to get his point now... Too many people put too much emphasis on a couple cc's....

joe_padavano

Um, no.

The 1965 330 used No. 2 heads with casting number 385101
The 1964 400 and 425 motors used "A" heads with casting number 398395

FYI, this is another example of an error in the Olds FAQ, which shows 385101 as the casting number for No. 1 heads. In fact, those heads used casting 381918.

Via3d

Sooooo Is it correct to say:

For least cost / best performance
- The W-31 heads are best alternate head due to the fact they have larger valves already, less machine work, and they are bolt-on....
- If larger valves not desired, then the #3 and #4 heads are the lowest cc heads that will bolt on. (39 degree bank)...
- I assume the machine work is more $$ to machine the 4A heads for performance....

- I still have not found much in way of documented data indicating port sizes comparisons on these heads (for the #3, 4, 6, 7) .... yet I see a lot of claims that certain heads flow better than another..... not consistent.
If the valves are same size then a better flowing head either has a variance in port sizes or in the casting itself, right ?
I have yet to see variances in casts rationalized with data/measurement indicating better flow. I assume it is insignificant.

-----------------------
This is the only port size data I have seen : (found in the oldsfaq stuff)

Intake, Exhaust Port Sizes

SB and BB intake ports are definitely different:Big Block
Head Floor Roof Width Height
A
B
C 0.470" 2.85" 1.37" 2.37"
D
E
F
G 0.470" 2.85" 1.37" 2.37"
Ga
H
J
K
Ka

Small Block
Head Floor Roof Width Height
1
2
3
4
5 0.435" 2.45" 1.30" 2.03"
6
7
7a
8 0.435" 2.45" 1.30" 2.03"
10
2A
3A
4A
5A
6A
7A

joe_padavano

Real, documented W-31 heads will NOT be "least cost", given the premium restorers will pay. It will be much less expensive to simply have larger valves installed in any other SBO head.

Via3d

Joe, You compared the 64 and 65, not 65 and 66 I indicated.

1966 #3 head cast number 389394 from a 394417 330 block, This is real, I have validated myself .

1965 .425
AHPS site shows two head types came on 425's:
Cast # 389395 A head part # 387573 (non-irrigation)
Cast # 389394 B head part # 391491 (irrigation)

I do not know the accuracy of this... I found it interesting it states the same cast head between a BBO and SBO used. There were a lot of parts interchangeable and changes occurring, it is not inconceivable.

Via3d

How much you think a pair of #5 or #6 W-31 heads will go for? just ball park range. Not for restoration purposes.... for performance Mongols.

lemoldsnut

I have several #3 #4 and a set of #5 as well as, a rebuilt set of #4A heads in stock

Email direct lemoldsnut@aol.com

or calls 541-815-4363

Larry

joe_padavano

The accuracy of that info is dismal. Olds NEVER used the same head castings on BBO and SBO motors. The ports are different sizes and there would be a severe mismatch without custom porting by hand (as I mentioned above when one uses a BBO head on a 403).

"A" heads are casting number 383821
"B" heads are casting number 389395
"C" heads are casting number 394548

"1" heads are casting number 381918
"2" heads are casting number 385101
"3" heads are casting number 389394

joe_padavano

They will always be priced for "restoration purposes". More to the point, there is no way to prove they are actually from a W-31 or simply from a run of the mill 350 with big valves installed later.

olds 307 and 403

Where in the hell is the 4A heads that have 72cc chambers? Mine CCd at 86cc. The intake is OK on the 4A head. The problem is the whole exhaust port and tiny valve. They are similar to the dreaded J head. Most use 330 or 350 heads because the flow similar on the intake side and better on the exhaust side, untouched. The real gain is the 15+cc smaller chambers allowing a decent cam to be used with the 9+ to 1 compression. If pistons need changed, the any of the BBO heads, except J's or aluminum heads make way more sense and give similar compression with much better flow.

joe_padavano

One more time. No one ever said that 4A heads have 72cc chambers. What was said was that the NHRA blueprint specs ALLOW you to mill the heads to get 72cc and still be legal for NHRA stock classes. You can go to NHRA.com and verify this for yourself. Once again, do NOT confuse NHRA blueprint specs with as-cast dimensions.

olds 307 and 403

Sorry Joe. Interesting you can remove 15cc and still be legal.

joe_padavano

As far as the NHRA is concerned, this is the factory-authorized blueprint spec. It has nothing to do with reality. Given that most of these 403s have about 7.9:1 CR from the factory, milling that much might get you close to 9:1.

brownbomber77

olds 307 and 403

There is also one dowel on each head that needs opened up, is it 5/16", think so.

brownbomber77

Yeah, I think so. Can’t remember when I mocked everything up.