differences in lt1's
 

i have a 94 z28 im trying to get a motor and tranny for.. it was a 6spd car so i would like a six speed. but other than that. what are the differences for the years of the lt1. also would a caprice or roadmaster lt1 work with the wiring block wise i know that the heads are different and i would swap for the aluminum ones. but what are all the diff. and how can i switch the car to obd2

Lets see I think these are all the variants of the lt1, someone will chime in if I miss something.

93 lt1 speed density, batch fire injectors by pcm, intake does not have fuel crossover bar in front part of manifold, 4l60 had no electronic controls for shifting. PCM has removeable prom for tuning OBD1

94 lt1 sequential fuel injection, intake has front fuel rail crossover, spline drive opti without venting, pcm does not have removeable prom OBD1
4l60e has electronic shift control by pcm
f body and corvette have aluminum heads, b body have iron heads

95 lt1 sequential fuel injection, intake has front fuel rail crossover, pin drive opti with venting, pcm does not have removeable prom OBD1
4l60e has electronic shift controls by pcm
f body and corvette have aluminum heads, b body have iron heads

96-97 lt1 sequential fuel injection, intake has front fuel rail crossover, pin drive opti with venting, pcm does not have removeable prom OBD2
4l60e has electronic shift controls by pcm
f body and corvette have aluminum heads, b body have iron heads

The corvette also had a 92 lt1, it had aluminum heads, but unsure of the rest, but is probably similar to the 93 lt1

hth

andy schuck

The iron heads on the B-bodies flowed better than the aluminum ones, but were heavier- Probably more durable, they were used for police service. The B-body LT1 never used the spline drive on the cam, they all had pins. Some years the vette had 4-bolt mains, I have seen discussion that some of the special limited F-bodies may have gotten them- not sure if that is true or not-

so should i steer away from the b body lt1's?

pretty much whats been said is covered... oh the corvette lt1 blocks were 4 bolt mains to the rest of the lt1s were 2 bolt...

Where are you getting that idea?

ok what changes need to be made to make it work

Are the rotating assembly and blocks the same?

Not necessarily however, watch out for the baby LT1 in some caprices 4.3 liter or 265 ci engine that looks like a LT1 but isn't a google search will give you the definitive means to ensure to don't get suckered.


Yes, all the 5.7 liter LT1s use same block and rotating assembly. Corvette has four bolt mains however, I wouldn't pay a big premium for a factory 4 bolt motor.

I believe the B bodies have a different cam that enhances low end grunt.
92 Corvette lt1s are rated 10 lbft lower than the 9400--96 lt1s

96 and up have OBDII and use a different timing cover and hub.

Mike

as long as the block is stamped 327 that should insure that it is an lt1 correct?

5.7L LT1's will have the number 327 in raised numbers on the side of the block.


EDIT: ^Yep.

Not quite... The early LT1s go the GM Pink rods.. Its not till 94 did they get the powdered metal rods that they are known for.

Better recheck your info. Even most 94's got pink rods...

There are a LOT of differences among the various year LT1s; GM just LOVES to change things.

Externally, the blocks, other than man cap bolts, are the same. You have to drop the pan to see if it's a 2 or 4 bolt version.

LT4s are a different animal.

OBDII calls for a different PCM, CPS and other subtle differences. Cams are, in some cases, model and year specific. PCM programming differs, # of 02s, knock sensors, Opti's differ, on and on. Stuff's all over the map.

Best way is to establish the CAR the engine came from, then research the engine specs for THAT car.

Jake

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