A recent chain of events has landed me a set of 5.3L heads. The intakes are nearly all ported (by me ), but the exhaust side remains untouched. I've spent a lot of time and effort on the intake, but I can't say the same for the exhaust.

On the intake I have,

*Removed casting marks on the straight way
*ConservativelySmoothed/slightly straightened the curved way (around the pushrod area), approximately .030"
*Streamlined the aluminum valve guide bosses
*Opened up the bowl area/removed swirl vane
*Raised the height/roof of the bowl area
*Removed the rocker arm bump

I still have to cartridge roll the intakes and finish relieving the chambers for bigger valves. They are currently relieved for LS1 valves over the 5.3L valves.

With only bowl work completed (prior to any runner work) they flowed 253 CFM on a very conservative flowbench (TR's) with a radiused inlet. That was with the puny 1.89 valvejob, with the chamber clearanced for an LS1 valve.

With a full-radiused valvejob hopefully the port won't quit flowing at .550" lift which is where the truck valve job held it up the first time these heads were on the bench. Flow was increasing at a very nice rate, but then suddenly stopped and leveled off.

So, just to recap; they were pocket ported then flowed, then ported more and are sitting on a shelf now.

Hopefully there is someone out there that just read what was done on the intake and can offer suggestions on the exhaust side. I'm sort of stuck right now.

I'm also not convinced on intake valve diameter. I'm trying to decide if a unshrouded 2.02 is better than a partially shrouded 2.04. I'm leaning towards the 2.02s, but I'm not sure on valve brand either.

So, if you have personally ported exhaust ports please offer some input.

I am also open for suggestions on what valves are preferred.

Thanks guys,
Ben T.