I have noticed that the 5.3 has a smaller bore size that the 5.7. I was wondering if I install the LS6 heads on my 5.3 will the valves hit the block or score the side of the cylinder wall? The heads will also be decked 0.0015. Help!!!

 

I would think after you deck them, it sould be pretty close. Regardless, I don't see how the valves will hit. Why are you doing LS6 heads? If your swaping stock for stock, I wouldn't expect anything to jump out and grab you (I'm no expert on that though). Personally, I would get a set of 6.0 heads with a mild P/P and go that route. Maybe a set of 4.8/5.3 stage 2's with 2.02/1.57 valves would be nice to. That's what I'm planning anyway (because I already have them). Good luck, when are you planning on doing it? Do a before and after dyno if you can. I'd like to see the #'s.

 

https://ls1tech.com/ubb/cgi-bin/ulti...c;f=1;t=004938

Here is a thread that has some good info.

 

Thank you for the replies. I am doing the LS6 heads because I bought them for $200. I am planing on doing this swap in about a month a month and a half.

 

The bores on the 5.3, 5.7 and 6.0 are all different. PTV (piston to valve) clearance should not be a issue even with decking due to the 5.3L's dished piston.

The only head where bore size seems to be and issue is the 6.0 to 5.3 swap. This leaves a fairly sizeable step between the top of the bore and the CC in the head. This is less appearant in the 6.0 to 5.7 or 5.3 to 5.7.

Richard