Okay, I've been doing my homework and the engine that I've decided on is the zz4 rotating assembly with the edelbrock aluminum heads (have EGR). I'm curious as to what kind of hp and torque I'll be making if I use my SLP headers, 3"exhaust, with a.)650cfm double pumper and aluminum intake b.)700cfm c.)750cfm d.)670cfm holley TBI and custom chip
I'd like to be seeing at least 330hp and 380 #t and still pass emmisions. If I must I'll swap in a larger cam to get those numbers. Please tell me these numbers aren't gonna happen :-)

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, Jon (91 RS too many mods to list)

 

Actually the ZZ4 is rated at 355hp and 406lbs of torque. I called GMPP and they told me that they used a 750cfm carb on the ZZ4 when they dynoed it. I am going to use a Speed Demon 750cfm secondary carb. I have heard great things about the Demon carbs. Do a little more research. You will need a Return line AFPR and a differnt throttle cable bracket. There is some other stuff. Post on the carb board or look at some of the other posts. There is a lot.

Oh and GMPP has a cam for the ZZ4 called the HOT cam. Its suppose to give you 40 extra hp but it will give you a loppy idle. Its up to you. Good luck keeping it emmisons legal.

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Eric Natzke
91 Firebird 305 TBI (ZZ4 summer of "01")
ASCD Ram Air Hood-3" custom exaust-Flowmaster 80 Series-No Cat-Edelbrock TES Headers (coated)-March Pulleys-TBI Spacer-K&N Open ELement-TransGo Shift Kit-B&M Supercooler 28,000 GVW-Hypertech Thermomaster-160 Stat-3:42 GM Gears-Auburn Posi Unit-Edlebrock Strut Tower Brace-MSD Superconducters-Accel Cap & Rotor
-Rapidfire Plugs-265/50/R15 Tires-Emmison's all Gone

http://members.aol.com/j007golden/91firebird.html


[This message has been edited by 91Bird305 (edited October 29, 2000).]

 

I'll let you know if mine passes emissions once I get it running. It should pass, given the fact that almost all parts are emissions legal (heads, cam, rockers, headers, intake, TBI).

I'm hoping for at least 325hp and 400tq. This combo is built for strong low-mid range power.
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'92 RS, ZZ4 10:1 350, Edelbrock 6085 heads, Crane 208/214 467/482 cam, GM/LT4 1.6 true roller rockers, Holley Projection TBI intake, Holley 670 TBI, SLP/Jet-Hot 1-5/8" headers, Catco 3" cat, Flowmaster 3" catback, Hughes 2500 stall converter, stock 700R4, Auburn Pro posi w/3.42, 17x9" SS rims w/BFG tires, Medium Quasar Blue w/white SS stripes, 48,000 miles....

[This message has been edited by Scott C (edited October 29, 2000).]

 

I know about the return line, the vacuum distrib. and the torque conv. lock up. I thought you could modify the TBI throttle cable bracket to work on carbs. Also I think I read somewhere that the TV cable works too with a little work.
I'd like to correct my last statement with using the zz4 rot. as., it's gonna be the caprice bottom end (only 2 bolt) with some heads that have EGR. Now that you brought up the edelbrocks being older design, I might look into getting different heads. Okay, now for the intake, you all think a 750cfm is my best bet for low-mid power and the flattest torque curve? I might just put on my friends 650cfm first before and dyno it with that. If it turns up numbers I like then I'll keep it. As far as emmisions legal, do you think a single plane or dual plane manifold is better? I know the dual plane will probably be more streatable and better low end, but what are some of the advantages to a single plain? I heard you get better high end hp but at a loss of torque. Need some input.

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, Jon (91 RS too many mods to list)