Olds guys, I need opinions on these heads

JAMCAR223

JAMCAR223

Royal Smart Person
Jun 6, 2014
1,226
113
Houston, TX.
I had wanted to use factory iron heads for my 403 build, so I purchased a set of #5 for a really fair price, with the intentions of building them up. I had contacted Jim @ J&S Machine about a Stage 1 buildup. His price was $1200 for what I wanted, but shipping iron heads both ways is not cheap. An alternative was use a set of #4 he had, and use his commercial account to ship just (1) time. I have verbally agreed to this, but he is taking his time, and not being very responsive with an ETA. Granted he has relocated and "retired" to Florida, but he agreed to build the heads. Without me asking - he has stated he would send me pics of the heads, along with an ETA on (3) occasions. That has not happened. So this morning I messaged him, and asked for the pics, along with valve & spring specs. Although he always responds, the story was the same... "I'll let you know on Sunday".

So now I am seriously considering another alternative. ProComp aluminum heads from Olds Rocket Parts. The fact that these heads are readily available, not to mention the weight savings- (which you know I am a fan of), has me wondering what you guys think? This may not matter to some of you guys, but it does to me... you know how the paint ALWAYS burns off the exhaust ports on Olds iron heads, and looks like crap? This will not happen with the aluminum heads - no paint to burn off. The price difference is $49. I bet the shipping is cheaper also.

 
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fleming442

fleming442

Rocket Powered Basset Hound
Dec 26, 2013
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aluminum heads with iron exhaust manifolds - most people do not do it that way. :LOL:
The 6.0 in my Silverado had iron manifolds on aluminum heads before I put headers on it.

I wouldn't deal with that guy though. He's thought to be involved with Lynn Pull-my-finger from Mondello in Paso Robles, CA- not proven, but enough to steer me away. If you want Pro Comps from a Mondello, look up Bernard Mondello Racing Engnes in Corona, CA.
I agree that it's not worth dumping the money into iron heads. Your best bet is to find a set used/already done.
 
Anubis

Anubis

Royal Smart Person
Mar 30, 2012
2,128
113
West Michigan
So now I am seriously considering another alternative. ProComp aluminum heads from Olds Rocket Parts. The fact that these heads are readily available, not to mention the weight savings- (which you know I am a fan of), has me wondering what you guys think? This may not matter to some of you guys, but it does to me... you know how the paint ALWAYS burns off the exhaust ports on Olds iron heads, and looks like crap? This will not happen with the aluminum heads - no paint to burn off. The price difference is $49. I bet the shipping is cheaper also.

No headers on this engine. I'll be using the Thornton 2.25" exhaust manifolds, as I am not dealing with leaky gaskets, and warpped header flanges, and poor fitment.

Curious what you guys will have to say about aluminum heads with iron exhaust manifolds - most people do not do it that way. :LOL:
I ran #5 heads on my 403. They made OK power but were heavy and were not the best option for detonation or more importantly flow. I always had to back off on timing, especially in hot weather to keep it from pinging. C/R was only in the 9's. After installing stainless BBO valves and doing all the other tricks they cost me small fortune (well over $1,200). BTW, I never had problems with leaky headers or paint burning (use a quality paint like POR engine paint).

If building another 403 I would definitely go with either the Procomps or Edelbrock aluminum heads. You probably already know aluminum heads are less prone to pre-ignition knock. I suggest you sell the #5 castings and go that route.

*Note* I am selling the ceramic coated long tube headers I had on my 442 if you're interested. They have a thick mount flange and don't leak
 
olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
6,109
113
Melville,Saskatchewan
What pistons? Procomp are good heads WHEN proper machining is done. Those heads have been measured and weren't anywhere close to 69cc. Plus without some die grinder work at the port opening they only flow 225 cfm intake vs 240 with minor work. As Procomp sells them flow and clearances are far from ideal. Benard Mondello and Cutlassefi build those heads properly. I would push 10 to 1 compression to take advantage of the bigger ports and flow of a properly built set.
 
JAMCAR223

JAMCAR223

Royal Smart Person
Jun 6, 2014
1,226
113
Houston, TX.
Pistons are undecided, due to different chamber volumes between the two heads. #4 heads from a 330ci SBO motor has 60cc chambers, that I could use a stock replacement piston, and gain quite a bit of compression over the the 403 heads. The ProComp BBO heads have 70cc (? questionable?) chambers, and I would need to use the KB Hyper pistons with a smaller dish, and deck the block/heads, to get more compression. It will cost me more ( roller rockers & KB pistons ) to go with the aluminum heads, but I could offset the cost by selling the #5 heads I already have. Still undecided 🤷‍♂️. I will wait a couple more days to see if Jim replies, before I make my decision
 
JAMCAR223

JAMCAR223

Royal Smart Person
Jun 6, 2014
1,226
113
Houston, TX.
403 comes stock with 4A heads with a chamber volume of 83cc's, and a compression ratio of 8.2:1. Now swap to the #4 heads with a chamber volume of 60cc's, and you get 10:1 compression, while using a stock replacement piston. That works for me. Plus, I can still use the Thornton 2.25" exhaust manifolds that I want to use.

Eng Head Head Stock *Cyl vol* New CRatio, w/ head of chamber size: [cc]
CID ID cc CR ci cc 57 60 64 67 75 79 83
330 3 60 9.0 5.16 84.5 9.29 9.00 8.64 8.39 7.79 7.53 7.29
330 4 60 9.0 5.16 84.5 9.29 9.00 8.64 8.39 7.79 7.53 7.29
350 5 64 9.0 5.47 89.6 9.68 9.37 9.00 8.74 8.13 7.85 7.60
350 6 64 9.0 5.47 89.6 9.68 9.37 9.00 8.74 8.13 7.85 7.60
350 7 64 8.2 6.08 99.6 8.74 8.50 8.20 7.99 7.48 7.26 7.05
350 7a 64 8.2 6.08 99.6 8.74 8.50 8.20 7.99 7.48 7.26 7.05
350 8 79 8.0 6.25 102.4 9.91 9.59 9.20 8.93 8.28 8.00 7.74
260 10 57 8.0 4.64 76.1 8.00 7.73 7.41 7.19 6.66 6.43 6.22
260 2A ?? 8.0 4.64 76.1 --can't do it w/o head cc info--( nobody cares anyway )
350 3A 75 8.0 6.25 102.4 9.49 9.20 8.84 8.59 8.00 7.74 7.49
403 4A 83 8.2 7.00 114.7 10.3 10.0 9.63 9.37 8.74 8.46 8.20
307 5A 67 8.2 5.33 87.3 9.13 8.83 8.46 8.20 7.60 7.33 7.09
307 7A 64 8.2 5.33 87.3 8.83 8.55 8.20 7.96 7.39 7.14 6.91

 
4

403Olds

Master Mechanic
May 31, 2014
324
43
South Central Ohio
I'd jump on those heads for that price. I dumped almost a grand in my 4A heads 10 years ago, had the 2.07 and 1.625 valves put in them. They runs well with Arias flat tops to get to 9.5 compression, but aluminum has more benefits plus at least the same flow, if not more than the reworked iron heads.
 
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500/600

500/600

G-Body Guru
Supporting Member
Nov 17, 2018
893
93
West Virginia
I can’t imagine even considering the stockers. If I could by aluminum for my 519 for twice that amount I’d be all over it.
 
olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
6,109
113
Melville,Saskatchewan
I can’t imagine even considering the stockers. If I could by aluminum for my 519 for twice that amount I’d be all over it.
The main use of 330 or early 350 heads is an easy compression boost on a stock 403 short block, same for a 350. Also the Procomp heads as cast are 83-84cc. Even with flat top pistons in a 350, 9 to 1 at best with tight quench. Procomp should offer the head as cast with a 70ish CC chamber and a blended port opening version with the larger chamber for the BBO. Honestly like Edelbrock offers for Pontiac, there should be a 67cc chamber option as well, we are not a big enough market unfortunately. I don't know if Olds Rocket Parts is going off the 77cc spec and doing a .060" cut, thinking so as their 69cc head actually measure 73cc I believe. That will give 10 to 1 with KB pistons. The Edelbrock head is definitely superior as cast with 265 CFM intake, arguably a better chamber shape and with much better parts but double the cost and still only one chamber option. With the .060" head mill, your intake will definitely need cut, another good reason for a smaller as cast chamber, nothing is bolt on like the chebby world, SBO stuff especially.
 
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