5.3 what does it take to make them worth while??
04-21-2003, 02:52 PM
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5.3 what does it take to make them worth while?? Ok what size valves would I need to have machined in and do they absolutly need milled?? Oh one more question will it work w/ a LS6 cam?? <img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" />
04-21-2003, 03:29 PM
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Re: 5.3 what does it take to make them worth while?? No milling really needed to gain compression over the 5.7 head. Not sure on the valve size either. You should check into one of the sponsor and they would be your best bet. Absolute Speed or TEA
04-22-2003, 01:52 PM
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Re: 5.3 what does it take to make them worth while?? Doing just a .003" surface mill to insure straightness and surface quality will get you a 10.8 to 1 CR. In my opinion, if using pump gas, that is certainly enough.
Most head porters (TEA, etc) install larger 2.02" intake valves and retain the stock 1.50" exhaust valve. This becomes the well known 'Stage 1.5' you keep hearing about. Of course, a quality porting job is a nessesity along with unshrouding the valves. Unshrouding the valves is important on 5.3L heads since the chambers are smaller than on 5.7 heads. Stick in a set of 918 springs and stock retainers, and you should be good to go.
Ron,
Most head porters (TEA, etc) install larger 2.02" intake valves and retain the stock 1.50" exhaust valve. This becomes the well known 'Stage 1.5' you keep hearing about. Of course, a quality porting job is a nessesity along with unshrouding the valves. Unshrouding the valves is important on 5.3L heads since the chambers are smaller than on 5.7 heads. Stick in a set of 918 springs and stock retainers, and you should be good to go.
Ron,
04-22-2003, 02:00 PM
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Re: 5.3 what does it take to make them worth while?? BTW, many folks like the 5.3 heads because to achieve a 63cc chamber (10.8-1 CR) on a set of 5.7 heads, you will need to mill them about .035"
Some folks with big cams worry about piston to valve clearance, and don't like to take too much of a cut on the head surfaces.
5.3 heads also will flow better than a 5.7 head on the exhaust side (if both heads have the same 1.50" exhaust valve and same porting technique)
Makes sense...
Some folks with big cams worry about piston to valve clearance, and don't like to take too much of a cut on the head surfaces.
5.3 heads also will flow better than a 5.7 head on the exhaust side (if both heads have the same 1.50" exhaust valve and same porting technique)
Makes sense...