The heads are ready for the 4.8 flat top pistoned 5.3 that is going into the ’87 Chevy Truck. These 862 cast heads have been fully home ported and used 2″ LS1 intake valves installed.
These heads were not flow tested, but I expect them to flow a little better then LS6 243 cast heads as my past heads have done.
I made the decision to run the 2″ valve because it was used so often in other LS motors and even in the HO5.3 with 243 heads, which is basically what I’m coping here.
I measured the throat and all diameters of the 5.3 valve seat vs the ones in a pair of LS1 heads. They came out to appear to be the same valve seat.
Springs are PAC 1218 .600″ Lift. Link below:
https://www.briantooleyracing.com/600-lift-pac-1218-beehive-valve-springs.html
Comp 511-16 Valve Stem Seals Here:
https://www.summitracing.com/parts/cca-511-16/overview/
UPDATE:
The heads were later pulled off of the truck and milled .045″ to achieve 11.4:1 Compression Ratio.
Plant 3D – Nozzle Catalog – Enhanced
Enhanced with New content and Duplicated metric versions of existing content. This has been done to help users drive bolt selection and bolt length output.