5.7 to a 5.3 swap
All in all both of the motors are pretty much the same.
One thing you are going to have to do is drill & tap the Ear on the drivers side of the Ironblock to bolt the Alternator too.
Look at the LS1 block and you will see what I mean.
Why not a 6.0l?
One thing you are going to have to do is drill & tap the Ear on the drivers side of the Ironblock to bolt the Alternator too.
Look at the LS1 block and you will see what I mean.
Why not a 6.0l?
I'm willing to bet he will be needing bigger Injectors for his build in the future.

unless your ls1 is alredy broke
Trending Topics
You need to drill the iron block with a 11/32" drill bit then tap it with a 1.5mm-10 tap to get eneough bolts going through the alternator bracket. Keep your drill normal to to the block
If the 5.3 was a drive-by-wire you probably want to keep the old harness and PCM too
The Best V8 Stories One Small Block at Time
One thing you are going to have to do is drill & tap the Ear on the drivers side of the Ironblock to bolt the Alternator too.
Look at the LS1 block and you will see what I mean.
Why not a 6.0l?
I'm willing to bet he will be needing bigger Injectors for his build in the future.

i have 250 bucks in my shortblock and it only had 30.000 miles also it was an 03 model so it has all the upgraded internals....its only 21cubes smaller....never even notice it once a power adder is added...
i put together a single mpt70 for friend and it now has around 5k miles at over 500rw with good tune, external pump, and 60lb'ers
1) Junkyard pullout 5.3
2) 317 heads
3) upgrade valve springs
4) ls6 cam
5) ls6 intake
6) FMIC and/or METH (i will run both)
7) accessories off ls1
you will be around 8.6:1 compression with 317's, so you can run 12psi without meth (but ill run it just incase)... I plan on running 12-15psi and 13-15* timming with my Garret GT70 turbo.... Its currently an sts setup but im gonna convert it to a Front mount truck maniflod setup.... hoping to make 600HP!!!!
Good luck with your build!!!! I will slowly be ordering parts as i have money, but work is slow right now and the cash flow is very little. So it might be a while!!!!
PS jfg455, Parish8, pwrtrip75 and im sure alot of other have all made 600hp+ on the 5.3L and the funny thing is the motors have all been running for years!!!!!!!









