Do I have to get LO3 heads machined to put in stiffer springs?
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Joined: Apr 2001
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From: East Windsor, NJ, 08520
Car: 2002 Harley Nightrain
Engine: twin cam 88ci
Transmission: manual
Do I have to get LO3 heads machined to put in stiffer springs?
Got a cam, springs, and all the gaskets- now I hear that Vortec heads need to be machined to use stiffer springs. Are LO3 heads the same way? The springs I'm planning on using are aftermarket springs that I took off of 415 casting heads. Do either of these heads use some super thin diameter spring or something?? I do plan on putting some comp cams springs back on the 415 heads by the way. Thanks
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Joined: Sep 2001
Posts: 6,111
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From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
On some aftermarket "stock diameter" springs, the inner damper
intefers on the guide boss root. You won't know yur situation until you try it.
You should measure the retainer to guide boss/seal clearance
to ensure there is at least .060" clearance at full valve lift.
The guide boss may need to be shortened for a high lift cam.
intefers on the guide boss root. You won't know yur situation until you try it.
You should measure the retainer to guide boss/seal clearance
to ensure there is at least .060" clearance at full valve lift.
The guide boss may need to be shortened for a high lift cam.
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Joined: Nov 2002
Posts: 51
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From: Alaska
If you want some great info on the Vortec Heads, see if you can get your hands on the Jan '03 issue of Chevy High Performance.
They have a great artical on the heads.
But the stock specs on the vortec are:
Valvespring Seat - 1.300" OD and the Guide diameter is 0.850"
They also state that you need to machine the valve guide diameter down if you want any more than 0.420" of lift.
Ive got some Vortec heads Im working on, and it looks like Im going to have to get some machine work done on them as well...But it should be worth while
They have a great artical on the heads.
But the stock specs on the vortec are:
Valvespring Seat - 1.300" OD and the Guide diameter is 0.850"
They also state that you need to machine the valve guide diameter down if you want any more than 0.420" of lift.
Ive got some Vortec heads Im working on, and it looks like Im going to have to get some machine work done on them as well...But it should be worth while
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