witch are the best flowing 273 heads#

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winstoninwisc

winstoninwisc

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need an opinion or fact wich 273 heads flowthe best stock
I have the 2465315 I think are the # or the 920 or are they like a X vs J 2.02 head I have a set for sale they are camano heads but another guy wants to buy a set but was told the 920 flowed better is there a difference 65 273 head flo head men or motor builders can you help us
 
no help here head builders where are u 273 guys any info motor builders

wylde step in with a thought rick ,crackedback, fishy come on thjs 1 stumped every body now way wheres are head builders ou812 brian u got any help on this 1 ??
 
The 318 302 casting would work well. Better than any of the 273 heads.
 
buy the iron magnum heads off ebay for $375 each assembled

brand new castings, 2.02/1.60 SS valves (might not fit on a small bore 273...), nice springs good to .550" lift, and they can come with the LA intake bolt pattern for LA intakes- you'd have to resetup the valvetrain (new pushrods/rockers ect..) but they'd outflow any production 273/318 head
 
A magnum head with stock valves would still probably be overkill for a 273. Not sure how well the valves would shroud in a small bore like that.
 
I really dont think there would be a difference in flow numbers for the few years of 273 heads. All pretty dismal with their small valves.
 
All the 273/318 heads probably flow really close to the same stock vs stock.
 
"RockerDude"'s got it right. All the "273 heads" flow about the same...later ones are open chambers. The "302" heads are actually 318 hi-swirl heads from the mid 80's, but do work well on the 273.
 
I think the problem with the magnum heads would be more than valve size. The magnum heads have essentially the same size ports as the 340/360. I think unless you were building a really nasty little 273, the port size might be too large with the magnum heads. Intake velocity is a balancing act. Too big a port and it slows down. Too small a port and there's not enough flow. I'm no cylinder head expert, but that's my understanding. ....and I know first hand about the port size of the magnum. I have magnum heads on my little 318 in the shop floor. I measured the ports to see if I needed to enlarge the openings for the Eddy air gap. The port sizes are the same. Maybe IQ52 will chime in. He's brilliant.
 
Okay first a disclaimer, I don't drink, never have.

Asking which 273 head is best stock, is like asking which glass of water from the kitchen faucet is the best, the first, second or third. The answer is, NONE OF THEM ARE BUDWEISER. Just drink the water or go to the store and get a Bud.
 
IQ52 said:
Okay first a disclaimer, I don't drink, never have.

Asking which 273 head is best stock, is like asking which glass of water from the kitchen faucet is the best, the first, second or third. The answer is, NONE OF THEM ARE BUDWEISER. Just drink the water or go to the store and get a Bud.
Click to expand...

I disagree...I think you were drinking when you wrote that. It is very helpful. :sleepy1::violent1:
 
Also, I think you would lose a lot of compression with any of those big valve heads. So it isn't just a bolt-on proposition. Others have mentioned the velocity issue.

The small bore 273 is really a different animal. Read the threads about 273 builds -- it can be done, but not by just bolting on "better" heads -- it's not a 318 in that regard.
 
All LA heads will interchange*. But there are 2 different port and valve sizes:
273/318s have small ports with the smaller 1.78/1.50 valves, as well as smaller combustion chambers.
340/360s have the big port heads with 1.88/1.60 valves** as well as larger combustion chambers.

* Big port heads will bolt up to the 273, but the 273 block will require notches for valve clearance.
Which leads to shrouding of the valves.

Hope this helps:)
 
HotLines said:
All LA heads will interchange*. But there are 2 different port and valve sizes:
273/318s have small ports with the smaller 1.78/1.50 valves, as well as smaller combustion chambers.
340/360s have the big port heads with 1.88/1.60 valves** as well as larger combustion chambers.

* Big port heads will bolt up to the 273, but the 273 block will require notches for valve clearance.
Which leads to shrouding of the valves.

Hope this helps:)
Click to expand...

X2. The 302 casting # heads are a good choice because they are similar to the stock 273 heads in chamber shape and size and the port size also. I believe the 302's flow a bit better and have a slightly bigger valve. (I am on my phone or i'd look up the valve size for sure) Stock 64-65 heads use their own intake also. Tmm
 
X3 on the 302 casting heads. Just be aware that they are sometimes cracked at the valve seats.
 
"302" castings have the same (1.74"/1.50") size valves as typical 273/318 heads. They have a more modern exhaust port and chamber shape. They were the best of the pre-magnum LA small port heads. They also respond well to larger valves and mild porting. A bore notch is typically used when fitting 2.02" intake valves to a 273, but it's probably not worth the hassle for the small gains over 1.88" valves. You could fit larger valves and port 273 heads and get similar results, although I don't know why anyone would bother unless they wished to retain the oddball 64-65 intake bolt angle.
 
I agree on the "302" 318 late model high swirl heads,the ports were redesigned for better flow,they were mostly used on vans and trucks for the most part although i believe the 318 4 barrel motors used in police cars may have used them as well. They are the smaller version of the famed "308" 1985 360 truck head that were so highly sought after before the magnums were introduced.
 
79-92 318 4 bbl cop car engines used standard 360 heads. They were 8:1 compression or so. There are better solutions out there.
 
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