Yes, a complete re-tune of everything would be required.

Displacement and overall airflow/fuel requirements will be completely difference with that kind of change.

Couldn't tell you exactly if those heads fit without PTV problems.

 

10-4
What is PTV?

 

Piston to valve clearance.

I just have never looked into using those heads on a LS3 block, so I don't really know if they are just a swap and go type thing.

 

Gotcha, thank you for explaining. Most of this goes beyond my grasp of knowledge. Figuring out exact compatibility has been a challenge and doing this project twice is already painful enough. It’s been a great learning experience though. My glass is still half full.

 

Thanks for all the help guys. Ended up going with a new LY6 short block from Thompson Motorsports.
Can’t say enough about their customer service and prices. Would highly recommend them. I’m excited to see how this engine feels with my 243 heads + cam and 11:1 compression.

 

Im close to your budget with my engine..assuming you have a good 5.3 block and bottom end and do all the labor yourself except machine work

 

sorry i completly missed this..congrats

 

Either way, thank you for looking out.