345 heads on a 392 - Off-Road Forums & Discussion Groups
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post #1 of (permalink) Old 01-08-2003, 03:57 PM
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345 heads on a 392

I think I am either going to rebuild the current heads on my 392, or install some off of a 345. Yes for starters my engine is the old style with tubes going to each head, but I was wondering what anybody else thought of doing this. I am considering the heads from a 345 because I don't think they will have to be rebuilt, and that I can get them for free. The only drawback to using these heads is I don't know if they are off of a 345 or a 304. Is there any difference between the two? Secondly, if I install the heads to get higher compression, will everything bolt up the same IE. intake manifold, exaust manifold, to block etc...

I would really like to know considering the heads are being brought to me tomorrow. I am tired of sticking valves so somthing has to be done. I am going to have the heads I am recieving magnafluxed to see if they are cracked, and if they aren't and if the consensus is that it will bolt up then in they will go.
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post #2 of (permalink) Old 01-09-2003, 03:22 PM
 
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Re: 345 heads on a 392

304 heads have a square intake port, 345 heads have a slotted (rectangular) intake port.

304 heads won't *correctly* bolt up to your intake.

Otherwise it's a bolt on affair.
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post #3 of (permalink) Old 01-11-2003, 11:43 AM
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Re: 345 heads on a 392

Then does that mean that in theory if I had a 304 intake I could use 304 heads on the 392 block?
That could be interesting, a 392 with a 2 bbl carb.
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post #4 of (permalink) Old 01-13-2003, 01:03 PM
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Re: 345 heads on a 392

The 304/266 are narrower than the 345/392 blocks.....the heads might fit...but you won't be able to get the intake manifold won't fit.
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post #5 of (permalink) Old 01-13-2003, 02:36 PM
 
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Re: 345 heads on a 392

Garscout beat me to it.

The heads bolt up (to a pre-IC 392) but the intake is too narrow to reach the heads, and if you put a 345/392 intake on, the big slotted port intake mis-matches the square-port 304 heads.

I've run a 2bbl 392 with a Holley 2210 on it before.. got my Travelall w/o an intake.. had an extra 2bbl 345 intake and a junk carb lying around.. worked fine for over a year until I found a better IC392 and ThermoQuad from a '74 and installed it.

I traded away the pre-IC block. I kept all three IC392s though. :-)
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