View Full Version : LG4 vs. L69 specs....?
ok, i have an 85 iroc ill be rebuilding next spring. it has the original lg4 and i want to keep the 305, this will be a cruising car, NOT a race car. However i want to upgrade the motor to L69 specs. I know the ecm chip is different, but what else is different? cam possibly? I'm gonna be rebuilding the whole motor myself along with swapping 80% of the original car into a new chasi(one that isnt rotted out)
NJ Torque
03-14-2009, 01:52 PM
I have a L69 I pulled from my monte you can have pual...
cam is from the l98 i do believe...
the C/R in the LG4 is 8.6:1
the C/R in the L69 is 9.5:1
L69 cam specs:
lift: Intake .410"
Exhaust .423"
Duration: Intake 320*
Exhaust 320*
"5.0 liter H.O. motor introduced mid-year (March 1, 1983). H.O. motor came with a higher lift and longer duration cam, dual snorkel intake system with '5.0 Liter H.O.' decal on air cleaner, specially calibrated Quadrajet carburetor, lightweight flywheel, electric cooling fan, bigger 2.75 inch exhaust and Corvette style wide mouth monolithic catalytic converter, 5.0 Liter H.O. exterior badging and interior emblem badging came standard with 3.73 rear axle gear. In 1983, L69 was only available with a 5 speed manual transmission."
all info taken from TGO
NJSPEEDER
03-14-2009, 03:03 PM
L69 had slightly better heads and cam. Same carb and intake, computer was set up with about 2 more degrees of base timing.
The advantage of the L69 was it opened up the 3.73 rear with disc brakes and posi available. That is where the bulk of it's potential came from
deadtrend1
03-14-2009, 03:18 PM
L69 had slightly better heads and cam. Same carb and intake, computer was set up with about 2 more degrees of base timing.
The advantage of the L69 was it opened up the 3.73 rear with disc brakes and posi available. That is where the bulk of it's potential came from
not to mention, it had the ugly, yet wonderful, dual snorkel intake that all the TBI'ers swear is the thing to have.
BigAls87Z28
03-16-2009, 07:05 PM
L69 had the future LB9 heads and the L98's cam, in a nut shell.
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