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350 heads on a 305


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Outcastz89's Avatar
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December 13th, 2008, 2:56 AM   #1  
350 heads on a 305

Hey everyone. Now I know 305 heads will work on a 350 if you grind the compression chamber out with a die grinder and everything. Will 350 heads work on a 305. I know they'll bolt right up. But will they actually work. Any downsides or upsides? Feel kinda dumb asking this question, but I wanna know. Thanks.

 
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December 13th, 2008, 6:24 AM   #2  
RE: 350 heads on a 305

They will work, Chevy used the same design until the 400. The only thing different should be the valve sizes & port volume (port volume might actually be the same, im not sure). Chevy could have produced a 350 head with the same CC chamber as a 305 but don't quote me on that. 350 head should have a 1.94 int and if its a basic 305 you will have a 1.72 int. If its a SS or Z28 305 you will have a 1.85 int. 307s also have the 1.94s.

Why would you want to grind the chamber? You must want to reduce the compression ratio huh? But making things work requires knowing what every other part being used has the potential of doing when applied to the current stuff you have. But thats my input.

 
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December 13th, 2008, 12:48 PM   #3  
RE: 350 heads on a 305

In yon olden days, we milled the head surface to bump the compression ratio. Looks like the 350 heads would flow better by just having larger valves. A mild aftermarket cam would probably do wonders too.

 
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December 13th, 2008, 4:33 PM   #4  
RE: 350 heads on a 305

I've heard that if you put 305 heads on a 350 you can make 20 more horsepower on a 350. A guy at work wants my heads off my 305 in my pickup for his 350 lol. So if I wanted to put 350 heads on my 305 they would work just fine without changing anything really? Don't know a whole lot about it.

 
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December 15th, 2008, 10:39 PM   #5  
RE: 350 heads on a 305

Well, I'm planning on doing the upper end on my engine real soon. So it would be nice to know if these heads will interchange. I'm just gonna bring it down to the shop and do it there on my own time since most of my tools are there and everything. I just don't want to run into any big problems and realize something won't work. I'm not just asking this to know, I actually need to know lol.

 
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December 15th, 2008, 11:03 PM   #6  
RE: 350 heads on a 305

What I want is that alki hemi for my Malibu....Damn!!!

 
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December 19th, 2008, 2:13 PM   #7  
RE: 350 heads on a 305

The 350 in my Nova had 305 Z28s on it. Its was a dog of anengine, heck a Beretta kept up with it lol looks like somebody does'nt know how to match performance between parts. O well those heads are goingto be used on the bomber car now with an actual 305 where they will do better.

 
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December 20th, 2008, 12:12 AM   #8  
RE: 350 heads on a 305

1Gary...it was a joke man! and you nailed it on the rest too.

 
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December 21st, 2008, 9:09 AM   #9  
RE: 350 heads on a 305

ORIGINAL: 1Gary

ORIGINAL: BigBoom360ci

" looks like somebody does'nt know how to match performance between parts."
Looks like why in god's green earth would I even care to be involved in a swap like this when the aftermarket heads that are so much better and are so cheap.Naw I am not going to turn back to my history when these kinds of heads where all we had to work with.


BTW-LOL,I would be afraid to take advise from a user name like "BigBoom360ci"!!!.It does kind of say it all,...........doesn't it??.
I was referring to one of the previous owners of the car Gary NOT YOU
.........relax, 350 bored .060 = 360.5 cid BTW. Thats where PART of my username came from. Other part, I just thought high compression = big boom......... just a little creativity there [sm=badbadbad.gif][sm=icon_rock.gif]

AND

My nova had them darn heads on it when I bought it. Slower than molasses of a car buddy AND the pinion shaft retaining screw was broken and many more problems with that damn thing. Pile of **** if you ask me, thats why I took it completely apart and rebuilding it so its not such a POS. I was actually thinking about making it into a dirt car but I thought no, its not rusty enough for that yet.

 
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December 23rd, 2008, 11:33 AM   #10  
RE: 350 heads on a 305

ORIGINAL: 1Gary

Turning it into a dirt car??????????.Huh???.You mean 6' of dirt??.[sm=icon_stickpoke.gif]
It wasn't a joke first of all. Second you saw it as a judgement towards you WHICH IT WAS NOT,for some reasonyou got fired up. [sm=forgetit.gif]

If that is what a 1970 Nova is worth to you is DIRT sure.....I think the sub-frame design is garbage. Car looks nice but it should have been a uni-body like mopars or the mustang. GM failed on Gen 1 Camaros & Gen 3 Novas etcframe wise. You can criticize me however you feel, your thoughts will not bother me since I do not worry about the assumptions/opinions of other people have about me.

You are right on the casting numbers - Unless somebody has shaved the heads. You would have to CC the chambers again, obviously.


 
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