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Former Member
Send PMManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
I've been building my dream motor since Oct., one step at a time (can't afford to buy one outright) all off Ebay. Found the ZZ4 short block cheap, supposed to be new, (not), found the heads, but after choosing to go with hot cam option I'm uncertain about the springs I've got. I was assured that they are the authentic ZZ4 springs ( which are said to handle "lift" up to .525 ) but I haven't seen enough of the ZZ4 variety to visually verify. ANYONE HAVE A CLOSE UP PIC HANDY ? I did a lot of reading on the matter recently but can't find my original source of info. The springs on my heads have an inner spring of an oval wire stock, and I thought I read it is what gave those springs their strength. My buddy is closing his shop on the 1st of Feb. (lease out) so I'm bringing my project home and had hoped to button it up before then. (Roller rockers and such) I'm hoping to avoid buying new springs ($$$$). The heads are on and I was about to put on the rockers and close it up but I'd sure like to know that I'm making the right choice. Any body out there have any positive ID for me. 
Jimmy B.
Just can't wait to get on the road again. 
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22720
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Don't know what the specs are on the springs you have, but I DO know the ovate-wire springs will not coil-bind at high lifts, compared to regular round-wound springs. Perhaps you could call your local GM/Chevy dealer, and ask if they have the correct ZZ4 springs in stock, then see if you could look and compare.
The only other way I know of to confirm what you have is to use a height mic, and a spring pressure tester to determine what they are. Sorry I couldn't be more help...
The only other way I know of to confirm what you have is to use a height mic, and a spring pressure tester to determine what they are. Sorry I couldn't be more help...
Joel Adams
C3VR Lifetime Member #56 
My Link 
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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Former Member
Send PMManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
Joel my buddy, you've already been a tremendous help, and , by the way, you "nailed it" on the flywheel stats. I only wish I could return the many favors you done for me. I'm not too terribly worried about the spring selection. It's kind of a matter of how often do I want to exceed 6500 RPM (safely) and I'm really not that kinda guy 
.
.Jimmy B.
Just can't wait to get on the road again.
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s
Jimmy, the ZZ4 comes with PN12551483 single spring OD is 1.32 in, and the pressure installed height is 101LBS @ 1.78 in.solid height is 1.22 inches. The same valve springs used in the 1996 LT4 engines and the ZZ4's not for use with cams with over .525 lift. I have the Hot LT4 cam and the lift is 0.525.this is what I have in my ZZ4 for valve springs. I did get the 1,94 intake valve size and the 1.50 exhaust valve size. My rocker arm set is upgraded to the 1.6;1 ratio..Help??
"I Love all Corvettes! LifeTime Member #60..Terry" 
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22720
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Thanks, Terry!! That's good data there. The part # helps, as does knowing that the ZZ4 is supposed to have single springs, not double...
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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Former Member
Send PMManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
Thanks guys, I really appreciate your help. I feel more confident to proceed without wasting money unnecessarily. I was assured they were the right springs, but I'm not quick to take the word of someone who's selling me something. At least the heads appear set up to handle some rpm's. They appear new, with a little cleanup work in the ports. I'm upgrading to 1.6 Roller rockers with 7/16" studs and guide plates. Looks like I'll be bringing it home in one piece ( the motor, not the car ). I'm hoping to get the motor changed out and repaint the car before summer. I'll post my progress.
aceinthehole 2008-01-25 14:55:14
PS This is all for the silver '81.
Jimmy B.
Just can't wait to get on the road again.
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Jimmy, the part number for the upgrade is set number # 12361322, 16 each for 7/16 stuud 1.6:1 ratio roller rocker arms..You could go to 1.7:1 ratio if you wanted, PN set 12361323..What kind of heads are u using?Terry
spielman5 2008-01-25 16:45:12
P.S. I think you may have to have the TALL Valve covers with the roller rockers?? Check..
"I Love all Corvettes! LifeTime Member #60..Terry"
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22720
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Remember, if you change the rocker arm ratio to a higher one, you will be mashing the valve springs closer to their bind point. If they are supposedly good for "up to .525" on the lift, and your advertised lift is close to that, going to a 1.7 ratio will most likely take it over the recommended limit...I'm assuming the specs for the springs are written using stock ratio rockers. Just a little food fer thought...
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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I stand corrected on the rockers, I have the 3/8 stud and you say 7/16 for you. I went back to the parts book and find 7/16 for big block and an option for 1.7:1 ratio but not in the small block. so you only can get 1.5:1 of 1.6:1 ratio for the ZZ4, they also caution on spring coil bind, retainer to seal clearance, piston to valve clearance and push rod clearance when using iron heads...Thanks Joel for the save..Terry
"I Love all Corvettes! LifeTime Member #60..Terry"
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Former Member
Send PMManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
Terry, you've been great. It's thanks to you for all the info and pics you've offered, and Joel, who is always willing to put himself out with tech research and stuff, and Sarge, for his "sig." statement that I even dared venture to this point. I love that ZZ4, and to think there are upgrades possible.......I'm in heaven ( this is once in a lifetime so I'm goin' for all the gusto I can get ) Don't have much money, so this is the only way I was ever going to get er done, and I'm prayin' that all goes well. The heads are off a ZZ4 that got an Owwie, not even broken in yet ( a nut into the cylinder ). They were magnafluxed and re valved but I failed to dig in to the spring history. The seller said the heads were reworked by the best shop in town and that the springs are original. I read somewhere about the superior spring qualities of the ZZ4. I thought it was in reference to the LT4 hot cam or possibly the kit that stated the cam kit was only for roller cams, and if used on the ZZ4 didn't require the spring change as those used had special inner spring oval wire design that would handle up to .525" of lift. Well... that's exactly what I identified on my heads but, my brain doesn't serve me as well as it once did, so with the info you guys gave me, I feel confident I'm OK with this spring setup anyway. Even with my dream motor almost finished I can't just swap it out, I've got some engineering to do on the bellcrank support, frame side. It broke off on the way up to Carson City. That was my silver/grey '81 left sittin in the parking lot sat. when we all went for the group pics 
. I was driving the wifes '78 (rootbeerfloat) ain't she a sweety. She never complained about my driving her car throughout the whole gathering.
Soooo, besides the welding job Id like to replace all the brakes and add some Hurst linkage for the Super T-10, and when that's under control, my buddy owes me a paint job,...... NICE 
.
. I was driving the wifes '78 (rootbeerfloat) ain't she a sweety. She never complained about my driving her car throughout the whole gathering.
Soooo, besides the welding job Id like to replace all the brakes and add some Hurst linkage for the Super T-10, and when that's under control, my buddy owes me a paint job,...... NICE . Jimmy B.
Just can't wait to get on the road again.
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