I was thinking about this earlier. I've got patriot 5.3 heads which I think are still stock 5.3 bore dia.(3.6xx or 3.7xx I think). Then I've got stock LS1 Gaskets from SDPC which are 3.898" bore. I'm also gonn order some 3.903" bore mahle pistons.

Is that gonna be a problem all these different bore sizes or am I okay? Its kinda bugging me. Thanks.

 

The stock gaskets are roughly 4". The ones I have here are actually 3.98", so, that's close enough. Gaskets are always gunna be a touch bigger than the bore. If you lay your gasket on the head and center it up, you should have .050" of deck showing all the way around. I believe the heads are cut for the F-body chamber from the get go. Part of the CNC program. Easy enough to check though, just break out the caliper and measure straight across the valves.

 

Thanks for the info Jason!

 

The 5.3 heads that we CNC are set up for the 3.900" bore.