yeah but whats the reason?

 

i think its something about it messes up the harmonics of the valvetrain and it can cause valve spring bind and other problems

aftermarket rockers is not necessary and wont gain any power if staying wit stock ratio. stepping up the ratio just increases lift and duration of the cam, IMO just get the lift and duration you want when you order your cam

 

So that explains why the L33 seems to make a bit more hp mod for mod. Hmm.

 

799 = 243 casting. Virtually no difference in ports or chambers as cast. GM has always used 2 casting numbers for each Gen 3 engine combination. For example early year 5.3l engnies have cast numbers 706 & 862. Early year 5.7l engines use 241 and 853 cast numbers. LS6 engines use 243 and 799 cast numbers. I don't have an explaination for this, just an observation.
A properly prepped pair of 5.3l heads will perform pretty similarly to stock 243 and 799 heads. The costs should be pretty similar too.

Richard

 

Well said Richard

 

how much do you guys charge to mill some heads?

 

We charge $70.00 to mill a pair of heads.

Richard

 

If you are going to use Richard, and I highly recommend that you do, talk to him about a set of his stage 1 ported 5.3 heads. I love mine . Well, at least I did back when I could actually drive my truck .

 

thanks thats what I needed...

 

guys how much should a 243 head be milled on a 07 5.3 ....i mean to raise my compression ..?