I will be getting some used stock 5.3 heads soon from a cool member on this site. I was going to get the basic Porting/Polishing, 5 angle valve job, and wanting to get them milled. How much could I go safely? The most I've heard is .040. Is there any drawbacks to this on a N/A motor? Thanks.

 

Anyone have an idea?

 

My Buddy Two Bit said you could go .050 and the intake would still match. Need pushrods and you get 10.8:1, Good deal for a na motor. Might need a little more fuel put to it.

 

Yea, I dont think you can go wrong with .040 or .050. Just get some shorter push rods though, 7.035s.

 

Do I have to get shorter pushrods when I get them milled?

Thanks Guys!

 

If you mill to much off it could cause a misalignment with your intake manifold and head.
Also when you mill the heads that much you have to get a shorter pushrod to correct for something,can't remember what they call it.

 

I didn't know that, thanks Clint!

 

No problem Richard. I learned most of this stuff from this board.

 

what kinda octane would u need with that ratio?