Mark F

I want to put a 5.3 in my LS1 car. What do i need to change on the wiring harness? can i use the same computer? What sensors are different? I plan on using my fuel rail, injectors and ls6 intake on the 5.3. Thanks

Dewey

iTrader: (1)

well first off I think you're an *** for doing this unless you've blown up your LS1

JohnHF

iTrader: (5)

yes he spun a bearing tonight. just trying to get it back on the road he is broke

Dewey

iTrader: (1)

you should be able to modify your existing harness to fit the 5.3. pretty much all of the parts for LS1s are the same as for the 5.3

Mark F

In what all is involved in doing that?

89IROC

iTrader: (2)

if ur just swapping the long block everything should work just fine

Dewey

iTrader: (1)

you will have to lengthen and shorten a few of the cables if my memory serves me correctly. you might have an extra connection or two as well.

89IROC

iTrader: (2)

what for? if hes using the long block and keeping everything else from his ls1 everything will be in the same location and everything...there are no external differences between an ls1 and lm7 other then block material...

5.3LJimmy

iTrader: (10)

You won't have to modify anything on the harness and all sensors are the same. You will have to drill and tap the engine block for the alternator bracket. This is very common and there are several threads with pictures on this site explaining where to drill and what size tap.