vortec head swap questions
04-17-2015, 02:40 PM
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Car: 1986 Trans Am
Engine: 327 .030 over sbc
Transmission: wc t5
Axle/Gears: stock
vortec head swap questions
Hey guys I am doing what you might call a budget build on a 355 and I got some vortec heads for free which was awesome but I sent them to my local machine shop and now they are like new. My question is what thickness head gasket should I go with. In a car craft article were they built a 305 with vortec heads they used 0.015-inch head gaskets. What do you guys think I should go with?
04-17-2015, 02:49 PM
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Car: 1988 Camaro
Engine: 355, 10.34:1, 249/252 @.050", IK200
Transmission: TH-400, 3500 stall 9.5" converter
Axle/Gears: Ford 9", detroit locker, 3.89 gears
Re: vortec head swap questions
Head gasket thickness needed will be based on your block's deck height and your piston's compression height.
The idea is to get around .035" to .045" quench height... Quench height is the space between the top of piston at TDC and the bottom flat quench pad on head.
Stock specs are 9.025" deck height, piston sits .025" in hole.
So you add gasket thickness to how much the piston sits in the hole.. .025 + .015" = .040" quench.
If your block has been 0 decked, then piston is flush with deck at TDC and you would want a .038" or .041" thick gasket
I have used the fel pro 1094 .015" thick head gaskets on many engine builds
The idea is to get around .035" to .045" quench height... Quench height is the space between the top of piston at TDC and the bottom flat quench pad on head.
Stock specs are 9.025" deck height, piston sits .025" in hole.
So you add gasket thickness to how much the piston sits in the hole.. .025 + .015" = .040" quench.
If your block has been 0 decked, then piston is flush with deck at TDC and you would want a .038" or .041" thick gasket
I have used the fel pro 1094 .015" thick head gaskets on many engine builds
04-17-2015, 09:52 PM
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Car: '86 Bird, 96 ImpalaSS, 98 C1500XCab
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Re: vortec head swap questions
If you're dealing with a stock shortblock, your deck clearance will be .025"-ish and you definitely should use the Felpro 1094 .015" gaskets.
04-18-2015, 07:45 AM
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Car: 1986 Trans Am
Engine: 327 .030 over sbc
Transmission: wc t5
Axle/Gears: stock
Re: vortec head swap questions
Thank you for the help guys. From what I understand the block may have been decked slightly when the previous owner had the motor gone through. I will try the ask the guy if he knows but it sounds like the 1094's are a safe bet. 
04-18-2015, 07:23 PM
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Car: 1988 Camaro
Engine: 355, 10.34:1, 249/252 @.050", IK200
Transmission: TH-400, 3500 stall 9.5" converter
Axle/Gears: Ford 9", detroit locker, 3.89 gears
Re: vortec head swap questions
Measure for your self. Then you know for sure and there is no guessing. You can measure how far the piston sits in the hole with a straight edge and a $2 feeler gauge once you have the heads off.
Just rotate the engine to bring piston to top dead center (TDC) as high as it will go. Lay a straight edge across the deck and slide feeler gauges under the straight edge ontop of piston.. Use the go, no go method. Meaning say a .025" gauge slides in tight, but a .026" will not go
Just rotate the engine to bring piston to top dead center (TDC) as high as it will go. Lay a straight edge across the deck and slide feeler gauges under the straight edge ontop of piston.. Use the go, no go method. Meaning say a .025" gauge slides in tight, but a .026" will not go
04-19-2015, 08:35 AM
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Car: 1986 Trans Am
Engine: 327 .030 over sbc
Transmission: wc t5
Axle/Gears: stock
Re: vortec head swap questions
Measure for your self. Then you know for sure and there is no guessing. You can measure how far the piston sits in the hole with a straight edge and a $2 feeler gauge once you have the heads off.
Just rotate the engine to bring piston to top dead center (TDC) as high as it will go. Lay a straight edge across the deck and slide feeler gauges under the straight edge ontop of piston.. Use the go, no go method. Meaning say a .025" gauge slides in tight, but a .026" will not go
Just rotate the engine to bring piston to top dead center (TDC) as high as it will go. Lay a straight edge across the deck and slide feeler gauges under the straight edge ontop of piston.. Use the go, no go method. Meaning say a .025" gauge slides in tight, but a .026" will not go
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