98_1LE

I have ordered ZZ3 heads, ZZ4 cam, SLP 1.75" headers and an Accel TPI base for my Formula. I'm not sure which rockers and runners to use. I saw a chart once detailing the length's and flow #'s for various runners, anyone know where it is??? Given the choice I would prefer stock appearing runners. Should I use 1.5 or 1.6 rockers? I know I'm going to have to burn a chip, is there anything I should consider? I plan to port match and conservatively clean up/polish the ports from end to end.

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87 Formula 350 13.94@96.67
98 Z28 1LE 13.15@107.59
1LE Owners Association

theformula

use accel runners as well.

try paceparts.com for the roller rockers. 1.6 made by Crane I believe for $280

Kevin91Z

iTrader: (1)

Check that Accel GP and see if you can get the base and the runners together for a deal. If not, AS&M runners are excellent too, but pricey.

Use the 1.5 roller rockers, unless you're upgrading the springs on those heads. The stock springs barely work with the ZZ4 cam, and wont work with any larger lift.

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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

98_1LE

Thanks. If I put new springs on (LT4 hotcam springs), would the 1.6 rockers make more power?

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87 Formula 350 13.94@96.67
98 Z28 1LE 13.15@107.59
1LE Owners Association

88IROCs

Runners (measured individually)
Stock....................203.17 cfm
ACCEL................242.02 cfm
Extrude/ACCEL...275.83 cfm
Super Ram............289.18 cfm

Intake manifold with 3/8 inch radiused intlet
.............................222.45 cfm

Stock intake manifold with runner
Stock....................198.72 cfm
ACCEL................213.52 cfm
Extrude/ACCEL....217.11 cfm
Super Ram............220.67 cfm

ACCEL Hi-Flow intake manifold with 3/8 inch
radiused inlet.........251.51 cfm

ACCEL Hi-Flow intake manifold with runner
Stock....................215.83 cfm
ACCEL................232.53 cfm
Extrude/ACCEL....243.21 cfm
Super Ram............240.24 cfm

Extrude-Honed ACCEL Hi-Flow intake
manifold with 3/8 inch radiused inlet
............................275.83 cfm

Extrude-Honed ACCEL Hi-Flow intake
manifold with Extrude/ACCEL runner
............................266.94 cfm

Kevin91Z

iTrader: (1)

I'm not fond of the LT4 springs, they dont have good seat pressure. I used Manley 1.25" race springs, but there are plenty of other good springs.

Dyno Don

iTrader: (7)

If you use the Manley springs you have to get the retainers too, because they stack higher at 1.750. They go about 125# at that height. And you can go to about .520 lift. If you want I'll get the part numbers for you.

Don>>>

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Chronologically challenged. But still kicking!
'92 CAMARO RS
305 TBI 5/spd (now TPI)
B4C Alt.
'69 camaro-BB/Lenco,1050 dominators, /Pump Gas/no drugs 8.97-150+/3200lbs.
SoCal Thirdgen F-Bodies