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Forums->Hot Heads Tech Talk->which heads to use

69fleetside
which heads to use


I'm new so be gentle. I just got a 1955 291 desoto. Everything checks out but the heads. The heads i have are part # 1327373 which according to my research are for the 276. My question is will these heads work on my engine?
The second question is are these good street performance heads? The block has a standard bore. I want to make about 300-350 hp with a single four barrel, 9:1-10:1 cr NA. Also what cam should i run? Any help would be appriciated.
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on: Sun 10 of Jul, 2011 [00:01 UTC] reads: 20691

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69fleetside
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Re: which heads to use
on: Sat 20 of Aug, 2011 [18:50 UTC] score: 0.00
Thank you for the help.

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billm
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Re: which heads to use
on: Mon 11 of Jul, 2011 [16:46 UTC] score: 0.00
George, you were right the first time! The 291 heads have larger valves than the 276 heads. The combustion chambers are also larger, but I don't know the volume difference between the two. The ports in the 276 and 291 heads appear to be identical. The only differences I can see are the chamber and valve bowl machining, and the 291 head has larger diameter exhaust valve seat inserts. 276 heads can be machined to use 291 valves, but some valve bowl work may be required to take advantage of them.
The bottom line is: If I had 291 heads, I'd use them. If I had good 276 heads, I'd use them as-is. If the 276 heads need new valves, I'd go for 291 valves and do a bit of bowl work. If so, valve stem and spring heights need to be checked. There are many other options, but money then becomes a big(ger) factor.
My two pennies, Bill

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George
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Re: which heads to use
on: Sun 10 of Jul, 2011 [16:38 UTC] score: 0.00
> I'm new so be gentle. I just got a 1955 291 desoto. Everything checks out but the heads. The heads i have are part # 1327373 which according to my research are for the 276. My question is will these heads work on my engine?
> The second question is are these good street performance heads? The block has a standard bore. I want to make about 300-350 hp with a single four barrel, 9:1-10:1 cr NA. Also what cam should i run? Any help would be appriciated.
The heads will bolt on but have smaller valves, you can put bigger valves in. The high deck 330/341/345 heads have bigger ports & valves than the 276/291. You'll need custom pistons. Ask Bob on the cam.

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George
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Re: Re: which heads to use
on: Sun 10 of Jul, 2011 [16:41 UTC] score: 0.00
> > I'm new so be gentle. I just got a 1955 291 desoto. Everything checks out but the heads. The heads i have are part # 1327373 which according to my research are for the 276. My question is will these heads work on my engine?
> > The second question is are these good street performance heads? The block has a standard bore. I want to make about 300-350 hp with a single four barrel, 9:1-10:1 cr NA. Also what cam should i run? Any help would be appriciated.
> The heads will bolt on but have smaller valves, you can put bigger valves in. The high deck 330/341/345 heads have bigger ports & valves than the 276/291. You'll need custom pistons. Ask Bob on the cam.
Crap! Guess my eye slid a line, 276 & 291 have same size valves!redface

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69fleetside
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Re: Re: Re: which heads to use
on: Fri 15 of Jul, 2011 [19:36 UTC] score: 0.00
> > > I'm new so be gentle. I just got a 1955 291 desoto. Everything checks out but the heads. The heads i have are part # 1327373 which according to my research are for the 276. My question is will these heads work on my engine?
> > > The second question is are these good street performance heads? The block has a standard bore. I want to make about 300-350 hp with a single four barrel, 9:1-10:1 cr NA. Also what cam should i run? Any help would be appriciated.
> > The heads will bolt on but have smaller valves, you can put bigger valves in. The high deck 330/341/345 heads have bigger ports & valves than the 276/291. You'll need custom pistons. Ask Bob on the cam.
> Crap! Guess my eye slid a line, 276 & 291 have same size valves!redface

Thank you George I appreciate the addvice. So are you saying that the 330/341/345 heads will fit and if so would those heads be an up grade in performance from the 276/291? Is thare a differance in port design or just larger valves? Would I then need an intake from a 330/341/345?

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George
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Re: Re: Re: Re: which heads to use
on: Fri 15 of Jul, 2011 [23:30 UTC] score: 0.00

>
> Thank you George I appreciate the addvice. So are you saying that the 330/341/345 heads will fit and if so would those heads be an up grade in performance from the 276/291? Is thare a differance in port design or just larger valves? Would I then need an intake from a 330/341/345?
>
You get bigger ports & valves. You'll still use a low deck intake.

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billm
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Re: Re: Re: Re: Re: which heads to use
on: Thu 21 of Jul, 2011 [15:35 UTC] score: 0.00
DeSoto heads will interchange across all engine sizes. You can use 276 heads on a 345, or 345 heads on a 276. Stepped dowel pins for head alignment may be required, but Hot Heads has them.
The biggest downside to using the tall deck heads is it's hard to find heads that aren't cracked. 40% of the tall deck heads I've seen are cracked. I've yet to see a cracked 276 or 291 head.
I've got a 276 with tall deck heads on it. Check my website "vintagev8s.com". There's a link to a YouTube video on the site.
I'm planning to replace the tall deck heads with reworked 276 heads. The tall deck heads are okay on a low deck engine, but I think reworked low deck heads will be better. Put some larger valves in them and do a little intake porting.
Bill


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