I have a 99 5.3 with the 862 hess on it. I've already ported and polished them in clash. I was able to pick up almost 10% from .100 -.600 lift range. I'm looking at putting in 2.00 intake valves since I can do some manly valves did 80 with the cutting off the seats. I've looked around but haven't found really any before and after % numbers on what people have gained from this or if it's worth in. Any advice would be greatly appreciated.

 

texas speed....a sponsor to the right has some 5.3 2.5 heads with oversized valves....look at their numbers.....i have a set and i noticed a huge difference all over but especially up top

 

Yes you are correct, but those are also cncd heads. I know that my hand p&p won't be anything close to them. So that's why I'm wondering if any has done it with home ported heads. I will agree thoae heads do work great. I had a set on my gto with the tq v2 cam.

 

I should be able to share the gains tomorrow .

 

Well between .400 -.600 lift I picked up almost 50cfm. Which I don't think is to bad for having 200 bucks into my heads. When I did the porting I didn't go crazy with it and just really did a clean up job on them.