Alright hopefully someone has some ideas on this because I am lost. This is the first engine i have ever done so I am not claming to be the best at it but I think I did it right. What I have is an 85 Z28 that HAD a 305 LG4 with a performer RPM and edelbrock 600 cfm carb. I was runnin 10.10 in the 1/8th mile and the car had 180,000 miles. After I tore the engine out i tore off the heads for the hek of it, and found out it had a cracked piston. So I figured my new engine (305L69, just rebuilt, bored 30 , ported heads, cam matched to performer RPM intake and 600 cfm carb, I also added high sump oil pump, high volume water pump, flowtech headers, accel super coil, and new distributor, and yanked off the A/C and all the Emissions) would run a hek of a lot better.... well I took it to the track and ran a 10.15 and my 60 foot is horrible now.. and it wasnt even spinning a lot off the line. I was hopin someone would have an idea... I know i need gears cause I have 273... but STILL it shouldnt be worse. Any help????

 

Well, so far it just doesn't make sense. Some questions i can think of is.. Is the engine broken in yet? Are all cylinders fireing? Is the computer screwed up? Are all the new components compatible to the Computer or to the intake? Oh well. i am not an expert.. i hope this helps

------------------
1990 Iroc-Z 305ci
*Flowmaster Exhaust (80 series)
*Hypertech Performance Chip & Airfoil
*Powerstop rotors
*8.8 mm Accel Wires
*Splitfire plugs
*MSD coil (48,000 volt)
*177.1 RWHP & 243.7RWTQ (keep in mind: 137,000 miles and only the above mods)

Future Mods:
350, TQ Conv., 3.42 gears, Headers, Ported plenum, Streetfigher 700R4 Trans., etc

AIM: Onfire4jesus324

My Car in Member Rides

 

What trans are you running?

 

You put a high rpm cam and intake intended for a 350 on a low displacement engine with a low rpm drivetrain behind it.

You should get a higher stall torque converter and better gears. That should get you in the 9's.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

Yeh, its broke in, 3500 miles. All cylinders are also firing. As for the computer, it doesnt have one anymore, thats why I got the new distributor (vacuum controlled rather than the computer controlled) and also got rid of the emissions crap. Hopefully the rear end and stall convertor help a lot. Thats my next project. I was thinking a 2000 stall for the 700r4 and 373 gears in a new posi rear end cause my posi is shot. Thanks for the help so far , you guys have any other ideas of stuff i should do?
(other than get a 350... cause i know thats what you are all thinking, lol ... I got the 305 again because I was sick of hearing Ford guys say it takes a 350 to beat their 302s)

 

I am closing this now since this not a tech ? about motor swaps.

------------------
86Z28, GM 350, Jet perf Q-jet & chip Dual snorkel air cleaner, Edelbrock performer intake, Edelbrock headers, Edelbrock cat-back, Off road pipe, MSD 6AL, Accel Super Coil, Taylor Spiro-pro wires, Rapid fire plugs, Jet fan switch, World class t-5, Hurst Short Throw Shifter, Ram Flywheel, Center force dual friction clutch,Aluminum drive shaft, BW disc rear 3.45's & a posi, PBR calipers, Earls braided brake lines, Polygrapite bushings all the way around, poly tranny mount & torque arm mount, Hotchkis lower control arms & panhard rod, Rancho limiter straps, KYB struts & shocks, Gm Wonderbar, Edelbrock strut tower brace, SSM sub frame connectors, Jamex lowering springs, Carbon metallic brake pads, Crossed drilled rotors, Mobil 1 Tranny fluid & motor oil, GM syntheic rear end oil, K&N, Grant stering wheel, 1,200 watt system, Jet Black Paint, 91 Z28 rims, 92 wing, Tinted windows.