i just purchased a 76 corvette to go along with the camaro, and it has a zz3 crate engine with a 4 speed. i have some unopened edelbrock rpm heads just sitting in my closet and the gears in my head just started turning. the motor right now is rated 345hp, would the rpms make a worthwile difference? i dont know the cc size on the zz3 heads, but the rpm's are 64cc. i also have an xtreme energy 268 (224 234 @.050 .498 lift) cam and a magnum 286 (236 236 @ .050 .49 lift). would do you think i should do, i dont really care i am just soooo excited and cant wait until i go pick it up.

The ZZ3 heads are 58cc, so you'd lose compression. ( But the ZZ3 valves are 1.94, where the RPMs are 2.02)

The ZZ3 uses a hydraulic roller cam.

ZZ3 hydraulic roller 208/221 @ .050, .474"/.510" lift, 112deg lobe sep

GM HO Aluminum heads 1.94"/1.50" valves

I understand wanting to use the parts you already have, but if you did the ZZ430 upgrades, you could "bolt on" 85 HP.

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My Camaros (http://hometown.aol.com/picturespic/70.html)

In this case the RPM heads are a bad idea. The ZZ3 heads have a 58cc combustion chamber, the RPM's have a 64cc chamber. This would drop the compression ratio signifigantly and hurt the power.
The ZZ3 has a Hyd roller cam, and I would be very hesitant to downgrade to a flat tappet cam.
There is power to be had from a cam swap, but you are going to spend ~$300 for a good hyd roller cam.

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1971 Camaro
383 stroker ~500HP
M21 4spd
12" brakes
16x10" Wheels
Autocross competitive
Engine Designer - The Speed Merchant, San Jose, CA
http://www.speedmerchant.com/

You could put the Edelbrocks on there and simply get a .028" GM PErformance Parts head gasket. You'd recover most of the lost compression since the ZZ3's came with a .053" thick head gasket. I believe the .028" gasket P/N is either 10105117 or 14096405. Check with GMPP.

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Pro-Touring 71

1996 LT4 Corvette Wheels are 17x8.5 front, 17x9.5 rear
Wheel adapters are 2.0" front, 2.5" rear
Baer Brakes four wheel discs
Fuel Injected ZZ4, custom burned EPROM, AFR heads, TPIS Mini-Ram intake,
Comp Camshaft, TH700R4 Transmission.
God Bless the USA
Project Photos on ULTM8Z project photo album (http://photos.yahoo.com/ultm8z)
See me in Chevy High Performance (http://chevyhiperformance.com/featuredvehicles/86018/)
ULTM8Z Website (http://www.ultm8z.com)

BTW that 268XE cam u have has 224/230@.050 duration and not 224/234

I agree with the posts to just leave the ZZ3 alone. Use those other parts for some other small block project down the road. Dropping the CR and using a flat-tappet cam in place of the excellent ZZ3 roller doesn't make sense to me. Aside from that, with the lowered CR that Comp cam would be a dog in the lower RPM ranges.



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'Silver Bullet' 1977 Z-28 413" SB
11.73 @ 115.10 on drag radials
Old Vortec combo:
12.15 @ 110.52

thanks for all of the advice. i guess i could just get a different cam if i wanted to upgrade and leave the heads for the camaro (which they were originally intended) http://www.nastyz28.com/ubb/smile.gif. i didnt know that the zz3 has a roller or else i wouldn't have even asked about the cam swap. i tried and tried to search for info about the zz3 but i guess i just suck at the internet. i also have an rpm air gap, which should bolt on since i believe the zz3 doesn't use the vortech style bolts.

if you tell me how to add some pics i will do it, but once again i suck at the internet.

<font face="Arial,Verdana" size="2">You could put the Edelbrocks on there and simply get a .028" GM PErformance Parts head gasket. You'd recover most of the lost compression since the ZZ3's came with a .053" thick head gasket.</font>You say that like you've done it before. http://www.nastyz28.com/ubb/wink.gif

Herberts has roller cams $175.00

<font face="Arial,Verdana" size="2">Originally posted by Todd80Z28:
You say that like you've done it before. http://www.nastyz28.com/ubb/wink.gif</font>

With my AFR's. http://www.nastyz28.com/ubb/biggrin.gif


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Pro-Touring 71

1996 LT4 Corvette Wheels are 17x8.5 front, 17x9.5 rear
Wheel adapters are 2.0" front, 2.5" rear
Baer Brakes four wheel discs
Fuel Injected ZZ4, custom burned EPROM, AFR heads, TPIS Mini-Ram intake,
Comp Camshaft, TH700R4 Transmission.
God Bless the USA
Project Photos on ULTM8Z project photo album (http://photos.yahoo.com/ultm8z)
See me in Chevy High Performance (http://chevyhiperformance.com/featuredvehicles/86018/)
ULTM8Z Website (http://www.ultm8z.com)