Will 1.8 ratio rocker arms be a problem with a mild cam(218/221 Lunati) since I have converted to the 5.3 heads? I have a broken rocker arm and just wondered if I might pick up a little power with the 1.8s. Anyone with the 5.3 heads running the 1.8 ratio and how is it working out?

 

Not An Issues, Deppends On Your Lobe Lift Though, Just Remember Add About .030 To You Cam Lift Now And That's What 1.8's Will Give You, Unless Your Cam Was Already Figured In With That Ratio Aready. My Recomendation Is Cranes 1.8 Quick Lift's 144759-16. I Have Used These, And They Work Excelent For Me And My Engines.

 

Thanks for the part number. I'm ordering these tonight.

 

Just do the calculation for the new lift.
(current lift/current rocker arm ratio)*new rocker arm ratio

 

What valve springs?

If you are indeed ordering the Cranes, best prices are on Vinci's web site, check the web specials.

 

I have patriot gold dual springs.

 

I have done this calculation, but how do I know if the result is acceptable for a ls1 with the 5.3 heads? Anyone running the 1.8s on an engine with 5.3 heads or know of any tech support that may know if this is OK??

 

As Long As The Head Has Not Been Milled, And Standard Length Valves Where Used In The Heads, Your Geometery Will Be Fine, But If Any Milling Or Somewhat Has Been Done, You Will More Than Likely Bottom The Plunger Out In The Lifter Upon Following Crane/vinci's Rocker Adjusting Procedure.

 

There is an article, repeated on Vinci's web site, about the Crane installation in a 5.3 truck. Take a peak at that, it might help with some of your questions.

 

I got my valve covers off and all the push rods and rockers are fine, but I decided to pull the oil pan drain plug and its covered with shavings. Could a lifter go bad and cause the symptoms of the backfiring at wot, and if so would my engine still run fine under normal driving conditions? My car has no symptoms until wot or maybe just before. I guess if it is a lifter, I have to drop the engine and pull the heads and I'm not looking forward to that.

 

Describe your shavings. Just fine fine superfine gray micropowder? Or full-blown shavings?

 

Some very fine powder but also some hair width pieces that aren't very long sticking up off the magnet.