I am looking at getting another f-body. How are the 83-84 L69 305's as far as performance? Also how are the 87-90 TBI 305's for performance? If you guys could take a guess at some stock 1/4 mile times for each, that would be cool. Thanks

 

I assume you're asking about what they ran new...

A 83 L69 Z28 (5-speed only) ran very low 15s, sometimes even 14s. An auto one (they introduced that in 84) ran about 2-3 tenths off that. A TBI car runs high 15s with a stick, low 16s auto. It depends alot on the options and therefore weight of the individual car.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Those L69s weren't slow at all. You could get a 190 horse 305 with a 5 speed and 3.73s, I had one in an 84 Z28, my first car, it was fast as heck for what is was!!

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End with 2.77:1 Gears.

Current Mods: LT4 HOT Cam, Comp Cams 1.52:1 Roller Rocker Arms, LPE High Flow TPI Baseplate, Edelbrock TES 1 5/8" Headers, Catco 3" High-Flow Catalytic Converter, Hooker 3" Aerochamber Cat-Back System, Transgo Shift Kit, Performance Resource Chip, Accel Ignition, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET: 14.32 @ 97.7mph
(corrected for elevation)

 

yeah, let's remember the for what it was. a new impala can run high 15's and that's fast for what it is, but it still isn't fast by any means, just enough to get out of it's own way. but i'd agree, low 15's to high 14's for a L69 model and high 15's to high 16's for an L03 depending on options.

 

With a gutted cat, TBI spacer, open element and some other small mods, My T5 305 TBI ran a 15.6 weighing about 3450 lbs with me in it.

 

whats the difference with the L69 engine to the other 305's? Wheres the extra HP come from and how come torqe doesnt increase when the HP did?