I know here lately there have been a lot of post about this topic, bare with me. I ran the car for the first time a couple of months ago, here is how it did:
60':2.095
1/8:9.367 @ 74.88 mph
1/4:14.581 @ 94.84 mph

The car is a '91 Z28, 350 TPI,it had a Custom PROM and Flowmaster Cat-Back system.
Since that run I have added K&N Filters, Accel 8.8mm Plug Wires,and a few "free" mods. The rest of the drivetrain is stock. I am running street tires also.

Are the numbers pretty good? What should I do next in order to get the car to run maybe high to mid 13's? Any help would be much appreciated.Thanks!

that sounds about right for a basically stock '91. my old 91 w/ accel base & slp runners, smoking on two cylinders, and no traction would run a 14.0 all day. have you done the ram air conversion and ported your plenum yet? those should help the mph.

Yes -I would say, it is a good time for the mods that you have made on your car but, you didn't say what gears you had. As you can see by my sig, I have close to the mods you have on your car and our times are not too far apart. What kind of mileage doe's your motor have? Mine is at 130,000.

The TPI intake system on our 350s were designed for a 305 cu.in. motor.(even the Corvette's are)If I had the money, I would first put "350 sized" parts on my 350. Start with a larger intake base,runners,TB and port out the plenum. You didn't say if you had an Adj. Fuel Pres. Reg or not but it is very necessary to tune the motor especially with your SD system. Headers are a very good idea when you have the intake side breathing that much better. A good cam will help get you to that 13.5 goal -go with something that will work with the long runners. /@.050/ 209-214 int. and 214-220 exh. with 112-115 lobe sep. angle works best on the TPIs. As far as Heads go, any of the high flowing sets that have good port velocity is what you should be looking for.

With a good setup you can get a long runner TPI to run Mid 12s or better on the motor only.

Hope this helped.
<hr align=center>
89 IROC-Z 5.7L
2.77 GEARS
K&Ns FILTERS
ALL FREE MODS
FLOWMASTER MUFFLER
PERFORMANCE RESOURCE CHIP
Best 1/4 E.T. 14.37 @ 95 MPH
Best 1/8 E.T. 9.22 @ 76 MPH
Best 60ft. 2.07


[This message has been edited by whiteroc (edited June 10, 2001).]

The car is running stock 3.23 gears. Should I go with a 3.55 gear maybe? Adj. Fuel Reg. is at the top of the stuff to add. Thanks for the help so far, keep it coming.

You're not getting a 3.55 gear unless you have a Ford 9" between the rear meats. The next step up is 3.42 but I doubt you'd see anything from that swap. Go with the 3.73s if you are intent on a gear swap.
bsa

Bolt on a set of headers, gut the cat, port the plenum, ad an adjustable fuel regulator & some VHT Traction adative & you should be running high 13's no prob. That's where my body's 350 Iroc is & we've never opened the motor, trans or rear.


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'91 Z28 1LE; 355, Sportsman II heads, Edelbrock TPI w/ 58mm TB, Tremec TKO 5-speed, 3.73's & much, much more

go with a used 9 bolt 3.45 gear and do the converter that would really help

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87 trans am 350 L98 aluminum heads,LT4 hot cam,slp runners,headers,y-pipe,edelbrock base,hi flo cat,air foil,ported plenum,t-5 tranny w/centerforce clutch and a 3.27 9bolt,ads strip chip,relocated iat sensor,hollowed maf

14.10@97mph w/2.01 60' 4SALE anyone want her?