ltr450ryder

iTrader: (13)

hey my brother has an 2002 silvy and wants to put a cam and mill head that he has a set of 317s that he was wonder if u can mill them down farn enought to raise the cr in a 5.3? if u guys could help out thanks alot

1slowz71

iTrader: (6)

can you mill them yes to get the cr up no! the stock 5.3 heads are 61cc and the 317's are 72 cc chambers!

05gmcsierra

iTrader: (3)

If ur brother has a 5.3 and he wants to mill his current heads just to let u know they r not 317s.. now if he has 317sa well I don't think its a good idea to put those on. U will need alot of milling to get it back to stock compression. Don't think u can even mill that much!

ltr450ryder

iTrader: (13)

Ok thanks he was just wondering I figured u could mill the like .60 to make them better for it.lol thanks again

ltr450ryder

iTrader: (13)

ok guys now my bro wants to know if he can mill 243 heads to get more cr out of his 5.3 cuz he wants like 10.1 ish for it any ideas for him? thanks

dmelvin

iTrader: (8)

That you can do. mine are milled .030 and I'm going to run a .040 head gasket, should put me at somewhere around 10.15:1... If I would have been the person to do the machine work to them, I probably would have milled them another .010

02gmcbandit

iTrader: (2)

personally id do the 243's .040 , thats what im about to do soon as i find a shop local to do the milling

05gmcsierra

iTrader: (3)

I believe like. 28 returns them to stock compression so .40 sounds about rt.. pick up ur compression a bit

ltr450ryder

iTrader: (13)

all right thanks guys glad to have ur help and what thickness gasket .40 or thicker and ill tell him to take .40 off the heads thanks again

dmelvin

iTrader: (8)

Stock gasket, I believe it's .051.

Shaving .040 and running a .040 gasket would be too tight for my liking, it'd be like shaving the heads .051

The only reason that I'm using the .040 gasket is because I bought my heads already milled .030 and I don't feel like going and having them milled another .010 since the nearest machine shop I trust to do it is over an hour and a half away.