i have a similar question to that one. so i have an '04 silverado 5.3 and i want to maybe swap it for an LS1 how would i do that? the guy that i was going to buy the LS1 off of said all i had to do was reuse the ignition coil off of my truck and the LS1 would work fine. is that true? would i need major upgrades to do on the ecu or even harness?

 

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