how many with LS1 in a 88-98 OBS chevy truck
#21
TECH Fanatic
iTrader: (23)
I put a 5.7 in it first with heads and cam with 11.5.1 compression ran real good on spray then went to turbo on 4#s had a boost spike blew a head gasket went to the track and ran a 8.21 at 92mph spinning, With my old rearend setup stock, 3.42 gear and all, The mounts i think were like $98, the shorties I have were $290, We got the wiring diagrams from my buddys work, We wired it up that way, The oil pressure wire that runs to the computer just run the other end to like your factory oil pressure gauge, same as water temp, volts, It was a quit easy swap, Just took some time, i am running dual walbro in line pumps with a 1to1 fuel pressure reg set at 59#s, Now it is a 6.0 on 10#s when I get it going again for the rearend swap we did and the new single turbo setup,
#23
10 Second Club
Thread Starter
well i finally decided to get pics of my conversion so here they are. keep in mind that i only use this truck for fishing and mudding so the motor is very dirty and i dont have any plans on cleaning it anytime soon LOL.
http://i162.photobucket.com/albums/t...che/96ls19.jpg
http://i162.photobucket.com/albums/t...che/96ls18.jpg
http://i162.photobucket.com/albums/t...che/96ls17.jpg
http://i162.photobucket.com/albums/t...che/96ls16.jpg
http://i162.photobucket.com/albums/t...che/96ls15.jpg
http://i162.photobucket.com/albums/t...che/96ls14.jpg
http://i162.photobucket.com/albums/t...che/96ls13.jpg
http://i162.photobucket.com/albums/t...che/96LS12.jpg
http://i162.photobucket.com/albums/t...che/96ls10.jpg
http://i162.photobucket.com/albums/t...ache/96LS1.jpg
http://i162.photobucket.com/albums/t...che/96ls19.jpg
http://i162.photobucket.com/albums/t...che/96ls18.jpg
http://i162.photobucket.com/albums/t...che/96ls17.jpg
http://i162.photobucket.com/albums/t...che/96ls16.jpg
http://i162.photobucket.com/albums/t...che/96ls15.jpg
http://i162.photobucket.com/albums/t...che/96ls14.jpg
http://i162.photobucket.com/albums/t...che/96ls13.jpg
http://i162.photobucket.com/albums/t...che/96LS12.jpg
http://i162.photobucket.com/albums/t...che/96ls10.jpg
http://i162.photobucket.com/albums/t...ache/96LS1.jpg
The following users liked this post:
Homer_Simpson (09-06-2022)
#24
TECH Fanatic
well i finally decided to get pics of my conversion so here they are. keep in mind that i only use this truck for fishing and mudding so the motor is very dirty and i dont have any plans on cleaning it anytime soon LOL.
http://i162.photobucket.com/albums/t...che/96ls19.jpg
http://i162.photobucket.com/albums/t...che/96ls18.jpg
http://i162.photobucket.com/albums/t...che/96ls17.jpg
http://i162.photobucket.com/albums/t...che/96ls16.jpg
http://i162.photobucket.com/albums/t...che/96ls15.jpg
http://i162.photobucket.com/albums/t...che/96ls14.jpg
http://i162.photobucket.com/albums/t...che/96ls13.jpg
http://i162.photobucket.com/albums/t...che/96LS12.jpg
http://i162.photobucket.com/albums/t...che/96ls10.jpg
http://i162.photobucket.com/albums/t...ache/96LS1.jpg
http://i162.photobucket.com/albums/t...che/96ls19.jpg
http://i162.photobucket.com/albums/t...che/96ls18.jpg
http://i162.photobucket.com/albums/t...che/96ls17.jpg
http://i162.photobucket.com/albums/t...che/96ls16.jpg
http://i162.photobucket.com/albums/t...che/96ls15.jpg
http://i162.photobucket.com/albums/t...che/96ls14.jpg
http://i162.photobucket.com/albums/t...che/96ls13.jpg
http://i162.photobucket.com/albums/t...che/96LS12.jpg
http://i162.photobucket.com/albums/t...che/96ls10.jpg
http://i162.photobucket.com/albums/t...ache/96LS1.jpg
Specs on engine mounts as well.
#25
TECH Junkie
iTrader: (50)
Wow, using the old style vortec harness and re-pinning it for the LS1 computer was a unique way of doing it. I think this is the first time I have seen anyone use the wiring from their old motor .
on the accy brackets too, that is also usually a stumbling block. Any pics of the brackets/setup?
on the accy brackets too, that is also usually a stumbling block. Any pics of the brackets/setup?
The following 2 users liked this post by oange ss:
Homer_Simpson (08-14-2022), Kustombuilt (02-20-2020)
#26
10 Second Club
Thread Starter
the acc brackets are the factory 5.7 vortex ones. i just welded up some adapter plates so they would bolt on. the engine mounts i also made my self. i used the orignal mount and welded a 1/4" steel plate to it that i drilled to bolt up the the LS1.
#27
10 Second Club
Thread Starter
#29
What are you guys using for the motor mounts and are you able to keep the ac compressor? I am about to start a 01 lq4 swap in a 98 tahoe 2wd 2dr and was curious. Also what about headers?
#32
TECH Addict
Ls1truck.com has a bunch of info on your swap. I used the dirty dingo motor mounts for the motor and the obs original motor mounts on the frame. Put motor in same location as old motor. Schoenfeld makes headers and Lextech on the ls1truck website makes an a/c bracket for your year truck.
#33
the wireing was easier then i thought. it is kind of hard to explain by typing but i will try. you just buy a LS1 computer, remove each pin one by one from your old 4 connector pcm and insert them in the correct location in the new 2 connecter. for example = tps 5 volt ref, black connector, pin 4, blue wire now goes into red connector pin 20 (i just made up these connectors for an example). this way you end up with all the pin locations for like a 99 camaro but the colors will acually be for a 96 truck. almost all the sensors are the same. you just have to swap the + and - for the crank sensor and relocate it from the front of the engine to the back. the TB and injector wires have to be extended (you will have to buy 8 injector connectors). you will also need to install one harness from scratch for the 8 coil packs but thats it.
on the acc. i just kept it very simple, i just used all the stock 96 ones. you only have to make 2 simple brackets. one for the left and one for the right. you just got to get the stock brackets to bolt up flush to the heads. then if you use a crank pulley and water pump for a 5.3L truck, the belt will line up (custom lenght of coarse). its complicated but simple.
then just make some engine mounts, use a 6.0L truck flywheel, drill it for a small bolt pattern, use a truck intake to clear your custom belt system and your done. for the exhaust, i did not care for headers so i just used stock manifolds and y pipe for a 6.0L SS truck and it fit perfect. after the y, i used a single borla muffler and a dump. with the manifolds and cat's it is very quiet.
this sounds like alot of work but it is (i believe) the cheapest way to do it. on the motor, i used a completey stock 99 LS1 out of a low milage vette, LS6 cam and springs, and stock unported 241 castings. i dynoed it before and after also. HP went from 175 to 285 (110rwhp gain). i also lost almost 200lbs off the nose, gained MPG (17 to 21 on freeway), and gain 2000 rpm (the vortex would drop off fast after 4k but the LS1 pulls to 6.2k easy). i love it but i did lose about 30 or so RW torque below 3500. i really feel that when i am towing but this i mainly a fishing truck so that is ok.
on the acc. i just kept it very simple, i just used all the stock 96 ones. you only have to make 2 simple brackets. one for the left and one for the right. you just got to get the stock brackets to bolt up flush to the heads. then if you use a crank pulley and water pump for a 5.3L truck, the belt will line up (custom lenght of coarse). its complicated but simple.
then just make some engine mounts, use a 6.0L truck flywheel, drill it for a small bolt pattern, use a truck intake to clear your custom belt system and your done. for the exhaust, i did not care for headers so i just used stock manifolds and y pipe for a 6.0L SS truck and it fit perfect. after the y, i used a single borla muffler and a dump. with the manifolds and cat's it is very quiet.
this sounds like alot of work but it is (i believe) the cheapest way to do it. on the motor, i used a completey stock 99 LS1 out of a low milage vette, LS6 cam and springs, and stock unported 241 castings. i dynoed it before and after also. HP went from 175 to 285 (110rwhp gain). i also lost almost 200lbs off the nose, gained MPG (17 to 21 on freeway), and gain 2000 rpm (the vortex would drop off fast after 4k but the LS1 pulls to 6.2k easy). i love it but i did lose about 30 or so RW torque below 3500. i really feel that when i am towing but this i mainly a fishing truck so that is ok.
#34
Gauges
I got the 99 obs 5.7 swapped with the 5.3ls and newer trans. Everything pretty much done, I have it running already.
I'm having trouble finding the wires I need for all the gauges to work. Can anyone help me find the wires I need, with some pictures please I would appreciate it.
I have the (green/blue pcm connectors)
I'm having trouble finding the wires I need for all the gauges to work. Can anyone help me find the wires I need, with some pictures please I would appreciate it.
I have the (green/blue pcm connectors)
#35
TECH Fanatic
iTrader: (1)
Speedo signal comes off the PCM green connector pin 50, and Tach is green connector pin 10.
Try LT1swap.com for pinouts and schematics
http://lt1swap.com/wiringharness.htm
Try LT1swap.com for pinouts and schematics
http://lt1swap.com/wiringharness.htm
The following users liked this post:
Homer_Simpson (09-06-2022)
#36
Gauges
Speedo signal comes off the PCM green connector pin 50, and Tach is green connector pin 10.
Try LT1swap.com for pinouts and schematics
http://lt1swap.com/wiringharness.htm
Try LT1swap.com for pinouts and schematics
http://lt1swap.com/wiringharness.htm