Prerun4fun13

iTrader: (6)

I have a set of 241 heads i am going to port and polish. I was wondering how far i can have them milled and still be able to clear my Magic Stick 3 without fly cutting?

Prerun4fun13

iTrader: (6)

TTT no one knows?

Dragkid1917

iTrader: (2)

no im wondering the same bout my 233/239... you have to do a ptv check. You could just buy .030 thousanths gaskats and thatll be like milling the heads .25

PREDATOR-Z

.003>.005 clean mill and only if absolutely necessary.
Otherwise just forget it

Prerun4fun13

iTrader: (6)

Is that because ill have PTV issues or is it just not worth it on those heads???

PREDATOR-Z

PTV issues, unless you want to flycut

hammertime

iTrader: (1)

Yes, but LS1 engines have a positive deck height. The piston crowns stick out anywhere from .005" - .010". You run those gaskets, and you'll be placing the head deck as close as .020" from the pistons - to close for comfort.

Besides that, you're still reducing PTV clearance. Probably need to flycut anyway.

That cam is a tight fit with stock head gaskets. Reducing clearance by milling or running thinner gaskets will require you to notch for clearance.

studderin

iTrader: (28)

I wouldnt go any closer, people say there ae fine. But I few times I've pulled the heads off the common stock long block MS3 setup. And had slight int. vavle contact. scary stuff.

Prerun4fun13

iTrader: (6)

So is it just a better idea just to run a set of ported 5.3 heads or a LS6 head?

PREDATOR-Z

No it is a better idea to follow proper procedures and measure PTV. If too tight then flycut or go with a smaller cam.

Black02SLPSS

iTrader: (5)

Hell if your taking your heads off to mill them you might as well flycut the pistons while their off.. just my .02 tho

LS1firebird95

dude you should have no problem milling the heads. I have 853 (99 ls1 heads) that are ported and are milled .055 that makes the heads a 54cc head over a 62 cc stock head. i have 2cc diamond pistons and my cam is a custom grind 228/236 581/601 113LSa. you should have no problem with milling them. and as far a flow# my 853 heads flow 308 cfm @ 600 lift intake side. that is more than the ported 243's offered by other companys. It is all who does the port work.

N4cer

iTrader: (11)

LS1firebird95:
853 heads had a 66cc chamber stock, not a 62.
I don't see that he's putting these on an engine with valve reliefs, so why is your clearance even relevant?

Prerun4fun13

iTrader: (6)

Hmmm i have alot to think about heads wise... I think im gonna go with a ported LS6 head or a 5.3 head.

hammertime

iTrader: (1)

If the heads you run are milled for smaller chambers (as opposed to welded), then you are going to have the same problem. If you insist on avoiding a flycut, reconsider your cam choice and stick with something under 230* and wider than 110 LSA to be safe. Even at that, you should still check.