Best Stock BB Heads?

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xLURKxDOGx

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Picked up a 71 HP 383 with stock 346 heads but they were pretty roached. My question is, I’ve done quite a bit of research on the forum but I have access to a set of 68 383 HP 906 and a later set of 452. Want to do minor port match and clean up. Which would be best for a hot street setup.

Thanks,
Jake
 
Most all the open chamber heads are real close to each other. The 906 is arguably "better" but IMO that's splittin hairs. Just pick one and go. That's what I would do.
 
906? 452? your choice since they are about the same thing. Since BB suffer from pistons being down in the hole at TDC compression always suffers. I would use the 67 model 915 close chambered head.
 
SGBARRACUDA said:
906? 452? your choice since they are about the same thing. Since BB suffer from pistons being down in the hole at TDC compression always suffers. I would use the 67 model 915 close chambered head.
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They seem to be worth gold from what I’ve seen. I was looking at an old hotrod.com article on a stock 383 they got 117 hp on basic add ones and I’ve been trying to use as much as that information as possible. They zero decked the block the went with forged flat top pistons, Edelbrock Manifold.

Jake
 
Back in the day it was 915 '67 heads. I used to have two pair. That was a hell of a long time ago.
 
SGBARRACUDA said:
If your going to zero deck with a piston/block decking than the 906 or 452 will work out.
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Yeah, I’m wondering if for the sake of the machine work if the 915 are a better option,

Jake
 
If you already HAVE 915 heads, go for it. If not, buy aluminum. You'll come out ahead of the game.
 
I have 2 sets of 346 heads and have compaired them with the 906 and they are basically the same, nobody likes the 346 because they came on the 72 up 400 440 b & c body motors
 
brian6pac said:
I have 2 sets of 346 heads and have compaired them with the 906 and they are basically the same, nobody likes the 346 because they came on the 72 up 400 440 b & c body motors
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Jim Laroy likes them. That's good enough for me.
 
Run whatever heads need less work. The 452's are supposedly easier to port, the sets I've done are not that hard to get to 265-275cfm @ 600. S/F...Ken M
 
Best as cast - the 906 "F" castings.
Best well ported - all pretty even.
Best for mild port work - I like the 346/452s due to the throat and bowl shape for low to mid lift flow. Best bang for the least time invested IMO.
 
moper said:
Best as cast - the 906 "F" castings.
Best well ported - all pretty even.
Best for mild port work - I like the 346/452s due to the throat and bowl shape for low to mid lift flow. Best bang for the least time invested IMO.
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Was that a later year 906? I have access to a few spots I can look just wonder if they were b/c/e body.

Thanks
 
I've never found a single year or model for that casting but I tend to buy engines, not cars. It's a std 906, with an F cast into it. My understanding is they are the most consistently cast 906s made. The SS and FAST guys run them. I think out of 15-20 sets of 906s over the years, I've had 2-3 individual heads that were Fs.
I would ask Dwayne Porter if he knows any specific years to look at. But really, once you go and modify them, any year is fine. The template porting was on the earlier heads and that's where the biggest gains are to be found. That and a very high quality valve job on modern equipment.
 
I agree with the sentiment of using whichever heads need the least amount of $$$ spent to make them servicable.

The “best” ootb stock std port I’ve tested was indeed a 906 “F” head.
However, not all “F” heads are great, and I’ve tested non-F heads that were better than some F heads.
They are after all just castings........ and they’re not all exactly the same.

For a novice who’s going to do a little clean up, imo the 346/902/452 heads are easier to do and have a higher chance of making real improvements to than the 906/915 heads.
For an experienced head porter who has the extra time it takes to make a 906/915 work....... they do have more potential.

That being said...... unless the cores you’re going to use need very little work....... you’ll be better off buy new aluminum heads....... from both a cost and performance standpoint.
 
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A stock 346 head usually flows 215-220 intake and mid-150’s exhaust @.500 lift, and the typical 906 can range from high-220’s to low-230’s, with the ex basically the same as the other heads....... in that mid-150 range.
The “really good” F heads can be in the mid/hi-230’s stock.

This is what a nice bowl job on a 346 looks like:
Flows 244/177@.500

2712FA04-2687-453F-B440-73DD3168CE76.jpeg


FC7E3925-35EA-4F97-9548-0E046184A3B7.jpeg
 
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Then, opening up the pushrod pinch and finishing off the exhaust port will get you to 251/185@.500 lift.

Those numbers are all using the stock 2.08/1.74 valves.

A9B72305-56C6-4648-B839-184DA115D53D.jpeg


0C6D507E-A20B-4431-876C-C9225F44159B.jpeg


I can’t tell you how many reworked stock BB Mopar heads I’ve tested over the years that didn’t flow as good as these(and most had more work done to them)........ and often they aren’t any better than if they’d had no porting(or sometimes even flowed less than a head that had no porting at all).

For a little perspective.....
The last set of Stealths I checked were 260/174@.500 ootb.

A set of 906’s with a fresh valve job and bowl blend(done by a shop, not by a diy’er) were 224/170@.500 lift.
 
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PRH said:
Then, opening up the pushrod pinch and finishing off the exhaust port will get you to 251/185@.500 lift.

Those numbers are all using the stock 2.08/1.74 valves.

View attachment 1715313587

View attachment 1715313588

I can’t tell you how many reworked stock BB Mopar heads I’ve tested over the years that didn’t flow as good as these(and most had more work done to them)........ and often they aren’t any better than if they’d had no porting(or sometimes even flowed less than a head that had no porting at all).

For a little perspective.....
The last set of Stealths I checked were 260/174@.500 ootb.

A set of 906’s with a fresh valve job and bowl blend(done by a shop, not by a diy’er) were 224/170@.500 lift.
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Thanks for all the helpful info as well as the pictures. I know theres porting templates out there, any chance you have a set to sell?

Jake
 
Lelo Dart said:
452 have hardened valve seats for unleaded fuel.
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I always overlook factory hardened seats when making decisions about heads. That "hardening" is only about .010" or so deep. Going to be gone the first valve job anyway.
 
I don’t know if you mean heads or templates to sell...... but no matter, I don’t have either.

With how cheap you can buy aftermarket heads these days, the OE head market is very small...... usually someone who has to use them because of class requirements....... or for resto people wanting the car to be correct.
If all you have is a decent set of cores, and fully restore them using all new parts, valve job, guides, ex seats, flat milling, etc...... it’s real close to what a set of Stealths cost.
That’s before any port work is done.

The best advice I can give you on diy-ing some bowl work on a set of OE heads is......... a little less porting is better than a little too much.
Also, the first two things I look at for assessing cores is....... how badly are they corroded, and how bad is the core shift.

Heads done like what’s in the pics, on a 440 built with the right combination of parts, could make 500hp on pump gas.
 
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There are some people such as myself who can do some cylinder head work and light machine work at home. For us, OE iron heads can still be less expensive than aluminum. I don't often have the "around" 2K dollars to just plunk down on heads, so for me, iron heads do still have some appeal........if however meager. lol
 
Stealths are still $1000 complete.... no?

The bare Speedmaster heads are often under $600/pair on ebag.

Obviously, if you’re equipped to do head work yourself, then you’ll have mostly just time invested in playing with the factory iron.

If you have to pay to have it done...... you’ll reach “new head money” pretty quickly refurbishing the factory stuff.
 
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PRH said:
Stealths are still $1000 complete.... no?

The bare Speedmaster heads are often under $600/pair on ebag.

Obviously, if you’re equipped to do head work yourself, then you’ll have mostly just time invested in playing with the factory iron.

If you have to pay to have it done...... you’ll reach “new head money” pretty quickly refurbishing the factory stuff.
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Exactly. But.......there's always the cost associated with making sure those new aluminum heads are "right". Even still with that added, you would probably come out ahead on aluminum if the iron heads need everything.
 
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