needmoremoney

Well, today i got around to check the P/V clearance with my large cam, with .30 milled 5.7 SII heads, here are the results: I clayed the top of the piston, put the head on, etc... Rotated the motor over one full revolution, it spun pretty smooth, unbolted everything, pulled the head off, and sure enough, the intake valve went right through the clay and just hardly hit the top of the piston . So now, once again I have to send off my BRAND NEW HEADS, and exchange them for 5.3 truck heads, milled only 3 thousands for straight-ness. Also, one question. It looks as though if i used the head gasket, the valves wouldn't touch, would .35-.40 thousands be to close to be safe? Would getting 5.3 heads solve this problem? do 5.3 truck heads flow just as good?

Fireball

iTrader: (21)

A few things...how did you have the setup during the check? I typically use an old headgasket (to simulate compressed thickness) and bolt the head down with 2 or so bolts. I use a real light check-spring to hold the valve and tighen up to zero lash. Then I spin the motor over.

.035 is too tight (trust me ) Most say go for .080 PV clearance though I'm running mine at .070

Ported 5.3s will flow as good as 5.7s. unmilled heads will buy you another .030 in PV clearance. Mix that with the compressed thickness of the gasket and you should be good to go

dand35th

cut reliefs in the pistons ?? lots of guys have done that recently..Isky, I think is the one that makes a tool.

Slowhawk

iTrader: (12)

I had about .050 clearence,then just used the isky tool and cut another .050 off.Took about 1.5 hours to cut all 8 pistons

chino_man279

iTrader: (7)

Where is the best place to get the Isky tool? Best price?
Joe

needmoremoney

I would like to have 11.1 compression, what will it take to have 5.3's to give me that?

Zeta

You can get it straight from ISKY. They sales guy who answers their phone.

I have a new and unused one for someone who wants it.