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Discussion Starter · #1 ·
ok guys i need some advice i have a 350 bored .030 stock crank,rods, has a comp 270hcam (224 dir.) and has been rebuilt already (but i have to move some pistons around since he put some in in wrong) but i would like to leave the crank,cam,etc.untuched and in place.

i have 77 model smog heads194-150 76cc which make 9-1 compression with the kieth black pistons i have in it (120's) also have performer Rpm intake,headers,edelbrock 600

i would like at least 300hp preferably more, and i don't know what i can do with these heads. and still run on pump gas (daily driver) what's yall's idea's im open to suggestions maybe even diffrent heads depending on cost (im broke) but may wait longer to spend some $ just don't want to sink much into it.

i have seen some good suggestions for other motors so let me know what yall think

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John Krenn
1970 malibu SS look-a-like well kinda
307/200-4r (soon to be 350 or 383)

Ft.Worth, Tx
 

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Id think that just bolting those heads on that combination with headers, will make 300 hp at less than 5000 rpm.

Do some bowl cleanup work on those heads & probably up that number to around 315-320hp.
at about the same speed (5000)


Other than that, save money for good cyl heads, which wont crack or pop the rocker studs out. With a really trick cylinder head on that engine it would probably make in the 400 hp range at about 5500 to 6000. Really trick being Brodix or AFR or Trick Flow 23°.
the latter being the least expensive $900.00
For a little less money, a set of World products Sportsman II's could be had with a corresponding drop in peak power, probably spend $700.00 & make 380 hp.

HTH
 

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John, I'm just guessing here, do you have #424's or #434's.I don't remember the exact #.I had a set of them on a ' 78 Z ,1.94/1.5. You could install 2.02/1.6 in them, or run them like they are.They have hardened seats for unleaded fuel, and you can shave them 20 or 30 thousandths to increase your compression a little.They are the thin casting smog heads, but are O.K. for up to @ 350hp, that's about tops.If you are in an econo rebuild , magnaflux them for cracks, shave them , get a good set of springs, a good valve job, and bolt them on.Should be a real good dependable engine
 

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882's are thin & prone to cracking. The upside is they have a relatively small port volume & marginally reasonable flow characteristics. If they arent cracked, clean up the casting flash on them, & run em. They'll work for 300 hp for sure. The benefit of the small port is it boosts low speed power. They are not a performance head by any means but if thats all you got, they'll work!
 

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A real cheap way to get more power with these heads is to use a steel shim gasket. This will increase your compression a little (to around 9.5) but more importantly it will tighten up your quench. This will let you run more advance with more compression and less of a tendence for detonation. A win-win situation.

I had older (heavier casting) 882's and with these gaskets, and an increase in spark advance, it made a noticable increase in power. I don't know how much more power but it was noticable.


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Pat Kelley
66 El Camino, daily driver
67 El Camino, STRIP/street
 

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John,
To the best of my knowledge, 1977 is the year that small block heads went to the thinner, light weight head castings. Most of the heads I have personally seen, and EVERY machinist I have ever talked to have or see cracks in these heads. Chev saved 3lb per head and as a result most of them are junk because of it (or soon will be junk). Any of the 1976-earlier heads would be a better choice.As far as I know, 98% of all 1.94 heads can be converted to 2.02 and can stand a fair amount of port and bowl work. If you can lacate some 73-76 heads, they will have factory induction hardened ex seats, so no need for adding hard seats. My whole point here is that ANY money you spend on these heads, may be money down the drain. IF they are NOT cracked now, chances are very good that they will be.

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Tom Parsons
 
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