I am going to be putting a forged bottom end and ported heads into my C5. That will leave me with a very low mileage LS1 shortblock and heads.

I also have an 03 RCSB Z71 with a 5.3. The question is can I use the LS1 shortblock and heads with all of the 5.3 bracketry/intake/sensors exhaust manifolds/etc and put the LS1 into the truck? Will It bolt up to my tranny ok?

Is there anything else that I would need to change to make this work?

Thanks.

 

everything will bolt up just fine. you will need to do a bit of tuning though.

 

everything should work fine the 5.3 heads will bump your compression to 11 to1 but they've got smaller valves. maybe have the set of 5.3's CNC'ed then you'd be moving.

 

Thanks for the info. I figured that it has to be pretty much a bolt in except for the tuning.

 

Keep us posted!

 

Been there done that. if you need anything pm me....

 

Just reuse all your truck accessories and belt routing. I personally don't think it will take any tuning to run well. But you would want to raise the rev limiter, shift points, and add timing, so tuning would benefit you.

 

mine is running fine on the stock tune... Trust me I'm dieing to get it tunrd though.

 

2003blue5.7

how much did the entire swap cost you?

 

That's great to hear that it will run fine on the stock tune. I assume that you used the stock 5.3 injectors? I have a Predator so I can do some tweeking. As soon as LS1Edit is available for the 03 trucks I'll upgrade mine and hit the dyno.

I am awaiting the new shortblock for the Vette (from LS1 Speed) and I can then free up the stock Vette stuff for the truck. I am hoping to be able to do this swap for the price of gaskets since I'll already have the LS1.