5.7 LS1/T56 swap for 305/5spd '89 C1500

[flattopwill]

Well, hopefully someone will correct me but It's a bit unclear with the 88-91 speedos cause they have the DRAC built into the gauge cluster and it's hard to access the wires. Here's how to do it on '92+ - http://www.ls1truck.com/forums/lsx-t...ol-wiring.html
If you just want it to work then just splice into the new vss wires and connect the old vss wires going to the cluster and it will work but is not tunable by the ECM for gear changes, tires sizes etc.

[tmjoki]

I am in the middle of the swap now on my 89 and i recommend getting the mounts that shift your engine back 1-2 inches. i bought the transdapt mount 4572 and the exhaust manifold on drivers side is so close to the rear brake lines the flange wont make it on. i am just going to weld and refab a second plate to my transdapt mounts.

[gl18rider]

I am in the middle of the swap now on my 89 and i recommend getting the mounts that shift your engine back 1-2 inches. i bought the transdapt mount 4572 and the exhaust manifold on drivers side is so close to the rear brake lines the flange wont make it on. i am just going to weld and refab a second plate to my transdapt mounts.

Can someone recommend which mount would provide the setback?

[low91]

Can someone recommend which mount would provide the setback?

Here ya go.
LS1 Conversion 1" Set Back Motor Mount Adapter Plates : eBay Motors (item 280500206464 end time May-29-10 23:07:35 PDT)

[gl18rider]

Thanks for the setback info and link. I did more research and talked to S&P. They had some interesting feedback. To start with, he thought the non-setback should work. He said it depended on the exhaust manifolds. TMJOKI, what year is the LS1 your putting in?
The other interesting approach he had was to keep the original computer for ABS, speedo, etc. I thought everyone was ditching their OBS PCM's and just using the new one? Is there any reason the new PCM would need the speedo if I have manual transmission? I thought I had a decent handle on the computer direction, but now I'm rethinking it.

[coastsidekid]

The other interesting approach he had was to keep the original computer for ABS, speedo, etc. I thought everyone was ditching their OBS PCM's and just using the new one? Is there any reason the new PCM would need the speedo if I have manual transmission? I thought I had a decent handle on the computer direction, but now I'm rethinking it.

Im curious if i need the computer or not too. Not quite sure on what exactly the computer controls

[tmjoki]

i got a full 5.3l setup from a 99 pickup. i know its not a true ls1 . From what i have been reading those dirty dingo mounts look good, but the ones on ebay are really cheap and look great. i have problems getting them in canada and shipping time is terrible so that is why i am going to just make something work.

[92 6.0]

I also got rid of my stock computer but mines a 92. I have a buddy that just put an 8.1 in his 90 model but upgraded to a 92-94 guage cluster.