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here's the deal, i have a freshly machined 1980 305, .030 over,(equals a whopping 310ci.) new 9.25 to 1 flat top pistons that was given to me. i know its not a 350, but i would like for it to pull balls out to about 5,000 rpm.
i;m thinking of a comp cams #k12-256-4, .449/.456 lift, .212/.218 duration,
an edelbrock air-gap intake, 600cfm edelbrock carb, 1 5/8" to 3" headers.
I have a set of heads from an original 84' trans am, (need to clean to see casting #s) but probably either the 416 or 601 HO heads. figuring to rework them with 1.94 intake 1.6 exhuast with some port and polishing.
not sure what i'm gonna put it in yet but it'll be backed with either a 4 or 5 speed. just another play toy.
i'd like to hear ya'lls opinions , suggestions or ideas.
roy
 

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Sounds like fun! I would do something a little different just to shift the money in another direction. If others agree then try back cutting the stock size valves, use the extra money that you would use on the bigger valves to have the heads ported/blended really well to work with the stock valve sizes. Then again I don't know if your seats are sunk or if perhaps vortec heads would be that much better and you would have new castings with all new parts in them.
 

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the #416 are the ones to use they have the intake runners of a 350 head. i have had a set reworked to 1.94 but you have to bowl blend them.
 

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also having the stock valve size ported and bowl blended would work well into 6000 rpm as long as their 1.84
 

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I see some info that off the shelf vortec heads with no port work are capable of 400hp but...they say the springs that it comes with can only handle .420" of lift so changing springs might add to your budget.
 

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Just an idea here but if your budget can afford it how about bolting on a small supercharger like a 142 or a 144? If you can keep it under the hood not many people will realize it's there until you put your foot into it. I've heard several comments like, "man I can't stand gear drives" when I'm idling at a light. Your "lowly" 305 could put some 350 and 400 owners to shame. Just imagine what the other person would say when you tell them they got beat by a 305. :thumbup:
 

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Discussion Starter #8
I don't think there will be a problem with the valve springs and lift. the K-kit from comp cams is supposed to come with them and matched to the cam.
porting and bowl blending sounds like it needs to be in the budget. i have no experience with the vortec style heads, so some research is in order. are they available with the 54-60cc combustion chambers? i'd hate to drop compression on this little motor. a supercharger would be sweet to play with, that will take some extra side work for cash, but very much possible.
thank you for the comments, keep em' coming.
roy
 

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runn141 said:
ive purchased the vortec heads and the said they will handle up to .475 lift
The vortec heads I was reading about had two different specs for valve lift. I really think the .420 lift ones were a very early release ones or the runt of the litter because the other ones I saw could handle lift around the figure you gave. I don't remember the exact figure now, that was last night.
 

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QuenchPiston said:
The vortec heads I was reading about had two different specs for valve lift. I really think the .420 lift ones were a very early release ones or the runt of the litter because the other ones I saw could handle lift around the figure you gave. I don't remember the exact figure now, that was last night.
i purchased these heads about 2 years ago
 

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If you move up to the bigger valves it would be wise to check the valve to bore clearence, in some cases the valve can hit the bore due to it`s small size. You also have to think about shrouding, the larger the valve the worse the shrouding results in less flow and flow is power.
 

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Blazin72 said:
Just an idea here but if your budget can afford it how about bolting on a small supercharger like a 142 or a 144? If you can keep it under the hood not many people will realize it's there until you put your foot into it. I've heard several comments like, "man I can't stand gear drives" when I'm idling at a light. Your "lowly" 305 could put some 350 and 400 owners to shame. Just imagine what the other person would say when you tell them they got beat by a 305. :thumbup:
that would work pretty good but he would have to use a 76cc chamber head from a 350 or 400 preferably rhe #882 casting with 1.94 valves to get the compression down
 

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runn141 said:
that would work pretty good but he would have to use a 76cc chamber head from a 350 or 400 preferably rhe #882 casting with 1.94 valves to get the compression down
Didn't a few 305's come with dished pistons? I just read about the early F cars coming with two different pistons and some other parts back in the early to mid 80's. Maybe more like mid 80's.
 

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QuenchPiston said:
Didn't a few 305's come with dished pistons? I just read about the early F cars coming with two different pistons and some other parts back in the early to mid 80's. Maybe more like mid 80's.
they were more like a bowl shape with no valve reliefs early 305s were different, i think ive got a 76 model with factory flattops in it. but with a supercharger i think it should have forged pistons in it.
 

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Yea, once you start putting thick head gaskets in there to reduce compression you probably ruin the quench affect and create more problems. How do the combustion chambers of the heads from a 350 engine work on a 305 bore? Is it ugly or does it work ok? I am more familiar with Mopar and Oldsmobile stuff.
 

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QuenchPiston said:
Yea, once you start putting thick head gaskets in there to reduce compression you probably ruin the quench affect and create more problems. How do the combustion chambers of the heads from a 350 engine work on a 305 bore? Is it ugly or does it work ok? I am more familiar with Mopar and Oldsmobile stuff.
they are open chamber design 1.94s fit good but anything bigger i dont think will work let alone run good.
 
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