Heads on a stock bore 305
08-29-2006, 09:15 AM
#1
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Heads on a stock bore 305
has anyone installed heads with larger 1.6" exhaust valves on a stock bore 305? Not concerned with any potential "shrouding" just wether its will physically clear the bore.
08-29-2006, 10:16 AM
#2
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Car: 1989 IROC-Z
Engine: 5.7L EFI LTR setup
Transmission: T-5 World Class
not sure . But I have also read on here ...that you can use a 74 cc head if they won;t clear . But it's hearsay .
08-29-2006, 04:04 PM
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Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
They may fit, but because of the tiny bore, the 1.5" valve will breathe better. Same deal with 1.94 and 2.02 intake valves... the 2.02 might fit, but the 1.94 will breathe better. Too close to the cylinder walls.
08-29-2006, 06:15 PM
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Car: 84 Z-28 Camaro
Engine: 383
Transmission: T-56
Axle/Gears: richmond 3.73, eaton posi
I can state for a fact that the old 2.02/1.60 "camel hump" heads' valves hit on a 305, I would assume any 2.02/1.60 head would
08-29-2006, 06:16 PM
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Car: 67 Firebird Convertible
Engine: LB9
Transmission: 700R4
Axle/Gears: 3.55
The aluminum 113 vette heads with stock valves and 58cc chamber is very popular with the 305 bunch. I bought a set for a stock LB9 and they work great.
08-29-2006, 08:13 PM
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Car: Tree Huggers
Engine: Do Not
Transmission: Appreciate Me.
IIRC someone had a pic looking up the bore of a 305 at some 113s. Not sure if they were stock size valves or not. :shrug:
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08-30-2006, 06:08 AM
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Car: 67 Firebird Convertible
Engine: LB9
Transmission: 700R4
Axle/Gears: 3.55
I've always heard that if you kept the stock size 350 valves, there would not be a problem.
08-30-2006, 05:58 PM
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Car: 84 Z-28 Camaro
Engine: 383
Transmission: T-56
Axle/Gears: richmond 3.73, eaton posi
what valves are we talking about here....the stock valves on most 350 heads are 1.94/1.50 with the possible exception of the corvette (I don't even think it received them since the early 70's...I have to look that up...)GM hasn't put 2.02/1.60 valves in ANY car since the late 60's early 70's the 1.94/1.50 heads will mechanically work but have shrouding problems on a 305.
08-30-2006, 06:03 PM
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Car: 84 Z-28 Camaro
Engine: 383
Transmission: T-56
Axle/Gears: richmond 3.73, eaton posi
ok....just looked it up....GM hasn't put ANY 2.02/1.60 valve heads on ANY production car(including the 'vette) since 1975 due to smog (this dose not include gen II and III engines...I'm sure someone will bring that up), they still sold them over the counter and still do.
08-30-2006, 07:44 PM
#12
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Wow, getting a lot of exactly what I'm not looking for.
If you haven't actually build such a combo, please don't post.
Not looking for "i think", or I heard" or GM did this or that in the 60's.
These are "416" 305 heads (tighter valve C/L spacing than 350 heads) with 1.94-1.60" valves going on a stock bore 305 with a mild cam
.447"/.442" peak lift) The exhaust valve is the issue. At what valve lift will it contact the stock cylinder bore edge?
If you haven't actually build such a combo, please don't post.
Not looking for "i think", or I heard" or GM did this or that in the 60's.
These are "416" 305 heads (tighter valve C/L spacing than 350 heads) with 1.94-1.60" valves going on a stock bore 305 with a mild cam
.447"/.442" peak lift) The exhaust valve is the issue. At what valve lift will it contact the stock cylinder bore edge?
08-30-2006, 08:05 PM
#13
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Car: Tree Huggers
Engine: Do Not
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Wow, giving out a lot of a pissy attitude. Why not install the damn things and then come enlighten all of us ignorant peasants instead of coming on and insinuating how dumb we are.
OR
Take what I offered and spend some time with the search function and find the damn pic and thread and see what that person had to say.
BUT
We'll just o as you asked...
Yes. Happy now? 
OR
Take what I offered and spend some time with the search function and find the damn pic and thread and see what that person had to say.
BUT
We'll just o as you asked...
08-30-2006, 08:39 PM
#14
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Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
Fbird is the one making the post here, as far as I know he's the one with the most experience porting 305 heads.
I thought YOU of all people F-bird, have done this the most.
I thought YOU of all people F-bird, have done this the most.
08-30-2006, 10:45 PM
#15
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Have only installed them on 350's. This actually going to be the first 305 motor I've messed with.
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