I have a set of 5.3s I have had milled 0.070" to get around 10.5:1CR. These are going on my Silverado and I want to know if I will have any PV clearance problems with the stock 5.3L cam.


I'm also thinking of putting the stock cam out of my 01Z28 into the truck (it is free and I DO NOT want to change the RPM band much/if any). Would I have clearance issues with that?


I want to find out ahead of time so IF I need to flycut the pistons, I can have the tool here when I START the swap (so the truck does not sit apart for a week+).

 

You might have fitment problems with the intake rather thatn P to V clearance.

 

Yes I beleive that .50- .55 is about as far as you can go with out running into fitment problems.

 

this is true. intake fit problems you may see. also, with .045" milled you see ~10.5 so you should see considerably more with .070. good luck, maybe try some HUGE gaskets

 

as I understand it (since nobody around here seems to know the pin height of a stock 5.3), 0.050" mill works out to 10.3:1 so 0.070" should be right around 10.7-10.8:1 and should be well within the limits of 91 with ceramic coated chambers.

 

10.4 with a stock .054 gasket.

 

The pin height is probably the same as a 5.7 it's the same crank and rods. The piston comes out of the hole between .006 and .008 depending on who measures.

I have .055 milled off my heads and I don't remember if they were 56 or 58 cc's when done.

A 224 cam with the heads mentioned above with 2" intake valves is tight on the ptv.

 

thanks! I don't plan to EVER go near that big on this truck (I want it to stay a TRUCK....I have the Camaro for nasty idle and no low end... )

 

Trust me I still use my truck as a truck. I tow a car trailer about once a week lately and there is constantly something sliding around in my bed.

Yank makes a converter that stalls to 3000 and retains all the stock towing ability.

But I am looking for a Nova for the new set-up.

 

Thats too much to mill. Intake might not fit right. Try a different mill number and then use a thinner head gasket.