LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Which LT1 motor would you choose for a transplant?

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Old Nov 5, 2002 | 09:32 PM
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Which LT1 motor would you choose for a transplant?

I'm considering transplanting an LT1 motor into my truck which currently has a '92 TPI motor. Reason being is the TPI requires 2 ecms, one for the TPI, another for the 4L60E transmission, which is a wiring nightmare and my be the reason I have never got it to run correctly or to its potential.
The LT1 ecm will controll both, not to mention all of the low end power and high end breathing that can be had from the LT1 compared to the TPI.
Which year LT1 would you think is best for a transplant?
So far here's what I know and why
1) 93-94 optispark not vented and some have not had good reliability with them. 95+ has vented optispark which is better.
2) 95 and below is ODB1 so it can be modded easily and still pass emmissions, which I'll have to fall for '94 emissions anyway since its a '94 Silverado it would go into.
3) I burn my own TPI eproms now, I think all LT1 use a flash editor, LT1 Edit correct?
*
Any other reason? So know I'm thinking the '95 would be the best bet.
Thanks
Old Nov 5, 2002 | 09:52 PM
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Ive got an lt1 in my truck.Mine is a 97 that has been converter to obd1.I had to run 2 pcms due to the body control module.But you wont have that problem.
Old Nov 5, 2002 | 10:10 PM
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My daily driver is a swap car with a 1996 LT-1, OBD II that is. I absolutely love it, but the OBD II is a real pain. There is not any cheap software for OBD II that I am aware of. If I had it to do over I would use the same engine, or perhaps a 95, but go OBD I for sure.

JMO,

Bill H
Old Nov 5, 2002 | 10:35 PM
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So far it looks like 95 or before.
Are all LT1's sequential fuel injected, SFI ? I was thinking either 93 or 93 and 94 may have been bank fired injection, maybe that was the 92 LT1 in the Vette, anyone know?
Old Nov 5, 2002 | 10:40 PM
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The 92-93 Vette LT1 and 93 F-body LT1's are batch fire, speed density motors.

As for 94+, it is easy to convert to a vented Opti, or from OBD-II to OBD-I, so I wouldn't make that a big issue.

But if you HAVE to choose, I'd say a 95 LT1, since it is OBD-I and a vented opti. You can re-flash it using LT1_Edit or Tunercat. Also, get one out of a Vette, since they have 4-bolt mains.
Old Nov 7, 2002 | 12:09 PM
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Thanks for the replies, looks like I'm on target going with the '95, but will not rule out the others depending on price.
Old Nov 7, 2002 | 01:36 PM
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You pretty much said it yourself already: 95. And, like Joe said, if possible, get one out of a Vette.

TS
Old Nov 7, 2002 | 03:04 PM
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FYI, i pulled a vette LT1 apart about a month ago for a swap and it was only a 2 bolt main, so not all vettes are 4 bolt as many think. I have also talked to some other people who have had the same experience.

Stay away from the 92-93 engines as stated. Any other year LT1 will work well. 94 are unvented opti, but thats an easy sway to vented. 95 are set up and ready to go. 96-97 are OBD2, but thats not too hard of a switch back over to OBD1
Old Nov 8, 2002 | 01:07 PM
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The Vettes with the LT4's probably have the 4-bolt mains since an LT4 motor has better flowing heads and a stronger bottom end, bigger cam, etc. Now, I'm not certain if all Vettes of that era came with an LT4 or if it was an option...
Old Nov 8, 2002 | 01:40 PM
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You can run 95/97 motor with a 94/95 PCM and a 94/95 knock sensor. That is what I am doing with my Chevy II.
Old Nov 8, 2002 | 02:10 PM
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FYI, i pulled a vette LT1 apart about a month ago for a swap and it was only a 2 bolt main, so not all vettes are 4 bolt as many think. I have also talked to some other people who have had the same experience.
I have heard that also. I pulled an engine out of a 95 T/A one time and it had a 4 bolt main in it.(Warranty job at the GM dealer I worked for) Go figure.. The Vettes are suspossed to have 4 bolts, f-bodys 2 bolts,but it looks like sometimes GM used whatever was available at the time.
Old Nov 8, 2002 | 02:56 PM
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Don't even bother with a 94 or a 93. (or a Vette 92)
94 may be acceptable, but still a PITA.

95-97 is the way to go. While '95 is THE BEST engine to use, in my opinion, converting a '96-'97 to OBDI is not an expensive job, plus you also get a newer engine too.
Old Dec 2, 2002 | 11:38 AM
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Originally posted by atljar
FYI, i pulled a vette LT1 apart about a month ago for a swap and it was only a 2 bolt main, so not all vettes are 4 bolt as many think. I have also talked to some other people who have had the same experience.

After a little more research, Vettes came with either the LT1 motor, which was basically the same as the LT1 in the F-bodies, or they could option for the LT4, which had the 4-bolt main, LT4 cam, better flowing heads.
An easy way to tell the difference is that the LT4 does not have an EGR valve at all which is normally loacated at the back of the plenum.
The LT4 cam had enough lobe overlap that the ERG was redundant and was not needed.
Old Dec 2, 2002 | 11:55 AM
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LT-4 was an option in the vettes. The LT-4 useses the same block as the LT-1. little better heads, different cam, different intake and some other minor changes like a less sensitive knock sensor. not all LT-4's had a 4 bolt main either just like not all vettes have the 4 bolt main. an LT-4 vete is semi rare. LT-4's came in the f-bodies in 97 as an option for the 30th anniversary. they were orange with white stripes.
Old Dec 2, 2002 | 12:42 PM
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1993, it's Speed Density like the TPI motor you have in your truck, 93s can be converted to 95 Vented just the same as a 94.



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