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1957 283 heads

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#3 ·
Off topic:

Nice looking car in your avatar – have just bought one the same!
 
#6 · (Edited)
I believe the difference was small combustion Chambers to raise the compression on hp engines with flat top pistons and 997 heads. I can't remember the combinations, but some used domed pistons to raise compression. I'm sure Mikey knows the combinations.

The 1x4 220 hp used the same 539 heads as the fi 283 hp engine, but had flat top pistons with no valve reliefs vs domed pistons on the fi. I always thought the 997's we're only used on one engine (2x4 270 maybe?) being the rarity.
 
#11 ·
The 997 heads were ONLY a 1957 head, used on 220, 245, 250, 270hp engines. They have become quite rare and VERY expensive. I see NO performance benefit whatsoever with these heads. Their main value is the 997 casting number and the tower symbols on the ends. Period!
In my opinion (and that may not be worth much), the 539 head is a better choice for performance. Even though it has a bigger combustion chamber than the 997 heads (59cc vs 55cc), the wall area around the valves is more unshrouded which, theoretically, should flow better.
With today's crap gasoline, the combination of a 539 head and flat top pistons would make about 9.5-10:1 compression, which would be compatible with today's gas.
Even though the 539 head is best known as the FI head on 1957 283/283hp engines, it was an EXTREMELY common head because it was also used on 220hp pass car 1x4 carb "Power Pack" engines. Thus, 539 heads are relatively common and much more reasonably priced than the 997 heads.
 
#12 ·
I'm right in the middle of this subject with my engine shop. I'm having my 283" engine gone through with new components and the pistons are special to get to 10.5:1 compression ratio with the 539 heads. Or so I'm told. The piston guy wants the heads to measure and insure that the pistons do not have conflicts with valves.
Back in 1962 I installed power pack heads (I assume they the were 539 series) on a new 340HP 327 short block. Cheep horse power as the new GM short block cost me $250! I'd give 10 times that today for one. There was no valve conflict with the pistons. So today my machine shop uses a piston manufacture that is unsure what domed pistons are needed without seeing the heads. Oh well better to be sure than sorry... Al
 
#14 ·
These are out of my original 548 283 bored 60 over, block was not decked, 539 power pak heads were not cut, no special springs etc. they gave a 10.5 - 1 compression, I had no problems...but your experience may be different, the pistons were bought over the counter in 1979.
 

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#15 ·
DZAUTO said:
The 997 heads were ONLY a 1957 head, used on 220, 245, 250, 270hp engines. They have become quite rare and VERY expensive. I see NO performance benefit whatsoever with these heads. Their main value is the 997 casting number and the tower symbols on the ends. Period!
In my opinion (and that may not be worth much), the 539 head is a better choice for performance. Even though it has a bigger combustion chamber than the 997 heads (59cc vs 55cc), the wall area around the valves is more unshrouded which, theoretically, should flow better.
With today's crap gasoline, the combination of a 539 head and flat top pistons would make about 9.5-10:1 compression, which would be compatible with today's gas.
Even though the 539 head is best known as the FI head on 1957 283/283hp engines, it was an EXTREMELY common head because it was also used on 220hp pass car 1x4 carb "Power Pack" engines. Thus, 539 heads are relatively common and much more reasonably priced than the 997 heads.
Click to expand...
I have the tower symbols on the front of my heads. Did the 539 heads have that symbol on them? I was under the impression that a 283 power pack engine had the 597 heads also?
 
#16 ·
SBC Head ID

Image
 
#19 ·
heads

DZAUTO said:
The 997 heads were ONLY a 1957 head, used on 220, 245, 250, 270hp engines. They have become quite rare and VERY expensive. I see NO performance benefit whatsoever with these heads. Their main value is the 997 casting number and the tower symbols on the ends. Period!
In my opinion (and that may not be worth much), the 539 head is a better choice for performance. Even though it has a bigger combustion chamber than the 997 heads (59cc vs 55cc), the wall area around the valves is more unshrouded which, theoretically, should flow better.
With today's crap gasoline, the combination of a 539 head and flat top pistons would make about 9.5-10:1 compression, which would be compatible with today's gas.
Even though the 539 head is best known as the FI head on 1957 283/283hp engines, it was an EXTREMELY common head because it was also used on 220hp pass car 1x4 carb "Power Pack" engines. Thus, 539 heads are relatively common and much more reasonably priced than the 997 heads.
Click to expand...
Tom: 997s on 220hp engines?
 
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