Another ? about 273 heads on a 318

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KevinB

KevinB

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I know this has been discussed here, but...

If you didn't see in my other thread I'm hopefully picking up a 66 Dart GT with a 273 soon, as a donor car for my Dart 318 with the goal of 320+hp.

My 318 dates from 1968

My original plan was to use KB 167 pistons to get close to zero deck height in my 318. However if I use the 273 heads and stock pistons will that gain me the compression I'm looking for? I'd like to be around 9.0-9.2. My other consideration was to take the 318 block to .030 over for more compression. Still a good idea if I'm using '66 273 closed chamber heads?

If I use the 273 heads I'll take them to get a valve job done with hardened seats...will I need larger ports to get the HP I'm after?

I had already bought Eagle I Beam rods, but if I use the stock pistons would it be better to use the stock rods as well?
 
I have done 66 273 heads on a 318 and thought it ran well; I don't think 13.92 in the 1/4 mile is slouchy; in my 65 Barracuda.

When I did mine, I put 1.88 intake and 1.6 valves in the heads, and had the heads cut .030. I measured, calculated just a lick over 9 to 1 compression with a completely stock rotater (crank, rods, pistons), I ran a thin MP head gasket.

It's a nice wake up on a teen with out breaking the bank, go for it.
 
JBurch said:
I have done 66 273 heads on a 318 and thought it ran well; I don't think 13.92 in the 1/4 mile is slouchy; in my 65 Barracuda.

When I did mine, I put 1.88 intake and 1.6 valves in the heads, and had the heads cut .030. I measured, calculated just a lick over 9 to 1 compression with a completely stock rotater (crank, rods, pistons), I ran a thin MP head gasket.

It's a nice wake up on a teen with out breaking the bank, go for it.
Click to expand...

Did you have to shave the intake manifold surfaces?
 
JBurch said:
I have done 66 273 heads on a 318 and thought it ran well; I don't think 13.92 in the 1/4 mile is slouchy; in my 65 Barracuda.

When I did mine, I put 1.88 intake and 1.6 valves in the heads, and had the heads cut .030. I measured, calculated just a lick over 9 to 1 compression with a completely stock rotater (crank, rods, pistons), I ran a thin MP head gasket.

It's a nice wake up on a teen with out breaking the bank, go for it.
Click to expand...

Mind sharing the cam, intake and exhaust, carb and rear gear?
 
jimmyray said:
Mind sharing the cam, intake and exhaust, carb and rear gear?
Click to expand...

The combo: Edelbrock Performer intake, 3310 Holley, Thorley "D" Dart headers, 3.55 gears, 225/70x14 rubber, Crane Blazer cam, MP 166K (what ever that means) converter, manual valve body in the 904.
 
krazykuda said:
You must check your parts first...

Check your true compression like this:

http://www.forabodiesonly.com/mopar/showthread.php?t=278215


I hav a thread where I was doing the same thing, but found out that the 67 273 heads come in at 63 cc not 57 cc like the books say... Not as much of a compression boost as I had wanted, but in the right direction....

http://www.forabodiesonly.com/mopar/showthread.php?t=322035
Click to expand...

The 57 CC is 'the minimum' based upon NHRA specs. Not what the
Cylinder Head Combustion Chamber CC'd out at the factory.
 
69 Cuda 440 said:
The 57 CC is 'the minimum' based upon NHRA specs. Not what the
Cylinder Head Combustion Chamber CC'd out at the factory.
Click to expand...

Obviously, mine were only decked to bring them back in flatness/square, and still were at 63 cc....
 
ArizonaKid said:
The 318 I have had 273 heads on it, the compression was about 9.0:1.
Click to expand...
I'm getting ready to do exactly what you did....wondering if you used a thin head gasket to get your 9.1? I saw a gasket that's like .029 thickness instead of the usual fel-pro .039" ..... using a .450" cam or basically a 340 cam.... see what happens.....
 
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