The Aeoheads are $499 a PAIR. And I believe you can ask for different springs when you buy them.
Ok, I goofed on that one. But I doubt the spring upgrade is free. And the 915/587 heads (larger port volume) are $599 a pair. Per the Shady Dell website, J head (915's) flows out of the box and with a stage 3 port ($750!, plus a $150 valve job)
LIFT------ASCAST---------PORTED (S3)
.100”----62.1/46.6---------62.1/51.8
.200”----112.1/99.4-------135.2/103.5
.300”----156.6/128.3-----198.7/135.2
.400”----193.2/137.3-----239.8/158.7
.450”----200.1/138.3-----253.9/169.7
.500”----200.1/139.7-----258.4/182.9
.550”----200.1/140.8-----264.9/186.3
.600”----200.8/141.5-----254.6/186.3
Same website, same flow bench, Edelbrock heads...
AS CAST OUT OF BOX
LIFT------IN/EX
.100"----67.0/N/A
.200"--128.3/105.2
.300"--184.5/139.0
.400"--224.6/163.8
.450"--239.4/171.8
.500"--249.4/176.6
.550"--259.4/179.4
.600"--264.9/182.8
.650"--267.3/183.2
.700"--267.3/183.8
So, Aeroheads 587/915 $599,+$80 for hardened seats, +$750 S3 port, +150 race valve job = $1,580 (plus whatever the better springs will cost)
Off the aerohead website
eddy 360 performers = $1335
The S3 J heads do outflow the eddy's on the intake side the whole way, especially in the middle. But the Eddy's outflow the J's up to .450" on the exhaust side. Plus with the aluminum heads I can run an extra point of compression and lose 40 lbs off the nose of the car...
My Indy EZs were bolt on out of the box and the engine runs perfectly. Only worry I have is the rocker shaft holddown studs that came from Hughes. They seem to be too short and won't bottom properly in the threads so had to use Loctite and take the small washers off.
Indy make a nice set of 360-?? heads for small blocks and they make excellent power but I do not know if you need a special manifold. Might be too much flow for what you are after. Bolting on Eddies is like a guy putting mag wheels on his car looking for more cornering performance.
The indy heads are really nice, but they also cost $2,500 a pair, and require indy's intake manifold and offset rockers...
Plus, I'm not just "bolting on eddy's" to an engine built for iron heads, the build took into account the compression bump needed for the aluminum heads and takes advantage of the heads using the cam. This isn't a stock engine with 8:1 compression that I'm slapping aftermarket heads on hoping for a big HP increase. Plus, should I decide in the future to go back and port the eddy's, an S3 port job on them flows like this...
STAGE 3 PORT WORK
LIFT------IN/EX
.100"----77.6/N/A
.200"--144.9/112.2
.300"--204.3/151.8
.400"--255.3/189.8
.450"--276.0/199.1
.500"--286.0/201.9
.550"--292.2/206.3
.600"--297.4/208.4
.650"--297.4/209.8
.700"--297.4/211.1
Where the S3 ported J heads would already be pretty much maxed out for flow...