99 WS-sick

iTrader: (2)

100% stock internals, never touched but i have to pull the heads due to header bolt broke inside head.im thinking of decking them .030. i haven't seen a lot of people doing it so idk if people just dont want to or its not good for these motors??? .030 is about the most i can go without decking the intake as well so im trying to say at about .030.if i can, how much would u say is safe and how long would the push-rods need to be? any other changes need to be made?

farmington

iTrader: (14)

if you're using a stock thickness head gasket, you'll need to go with a pushrod that's .025 shorter (because they don't make one .030 shorter). You'll pick up almost a point of compression. If you have a cam in it, you might have problems with PTV so check it.

99 WS-sick

iTrader: (2)

ok so even though the stock cam in the 99 ls1 is .500/.500 lift that wont effect the piston to valve clearance? and how much more compression do u think it will gain? its already 10.5:1 stock

SOMbitch

iTrader: (8)

Lift has very little affect on ptv since highest lift occurs near BDC. It is duration that that leaves the valves hanging open longer that causes ptv issues. Since you have ls1 heads you are @ 10.25:1 CR so shaving .030 will put you about 11:1 CR with a GM MLS gasket.

99 WS-sick

iTrader: (2)

Would this benefit me to shave them with everything eles stock? Ill be doing a cam at tax time. Would 93 octane be ok to run?

Damian

iTrader: (89)

Just an FYI, it's highly recommended against using a GM MLS gasket on 853 heads due to the "notch".

OP. I wouldn't cut them .030. Not that it would hurt anything, it'll just greatly reduce your range of options on camshafts. With .030 cut, you're gonna have PTV problems with anything over a 228 camshaft.

I'd do .020, Felpro GRAPHITE head gaskets, and I'd have a reputable machine shop go ahead and do a basic valve job. A basic valve job can be done for around $100, and does a world of good. Have them clean up the seats, lap the valves, etc. Mind as well go ahead and replace the valve seals too, they're only $25 through Felpro.

You shouldn't need a shorter pushrod cutting .020 off, with a stock camshaft. Preload will be a little on the high side, but it should be fine.

SOMbitch

iTrader: (8)

Yeah I forgot about the stupid notch on 853's You might wanna do some new springs while you are at it and and you can upgrade to some LS6 springs for around $65-$70

As far as HP gains I would guess milling would get you 10hp or so. I agree with Damien that if you wanna keep your cam options open then just get a resurface which will be about .005.

If it was me though I would just beg/borrow/steal until I could come up with some 243/799's. They are much better untouched and have way more potential down the road...

99 WS-sick

iTrader: (2)

ok, the machine work is NP to do because my best friend owns and operates a machine shop ( i work there in my free time) i can get the complete rebuild kit with pistons and full gasket set for $700 and machine work is free. wat would be a good deal on some 243 heads?