318 heads on a 273????

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Badart

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I have decided to freshen up the Hipo 273 in my 65 barracuda a little. Before we got it running it hadn't ran in about 20 years and it has some compression issues, but doesn't smoke. I want to pull apart the top end and check it out and pop in a new head gasket set anyway. I recently picked up a set of rebuilt 318 smog heads with the casting number of 4027163 for $80. LOL I couldn't pass it up. I know that all of the 318 heads had around 58-60cc combustion chamber, but what was it for the hipo 273 and how much compression drop will I have by going to the 318 heads?

I figure that I can take advantage of the rebuilt 318 heads and swap out to an aluminum intake, I have a couple to choose from and here are my options, Eddy Performer or Holley Street Dominator?

I will also be using a Holley 600 Double Pumper that I have laying around. I also just plan on running the factory 273 exhaust manifolds and exhaust. What are your thoughts? Here are the heads that I picked up.
 

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What head gaskets would you recommend for this application? It looks like the heads have been shaved a little, but don't know how much.
 
The 273 heads you have now are most likely 178 heads which have a CC of 64. The 163 heads you're thinking of switching to have a CC of about 70 and possibly as high as 72 unless they've been milled. The picture says they haven't.
Here's a calculator. Your bore is 3.63 and your stroke is 3.31 Gasket thickness is about .040 and your gasket bore is 3.75. Your deck height should be around zero but won't matter if you use the same number for both when comparing.
http://www.gtsparkplugs.com/CompRatioCalc.html
 
You'll need to drill, tap, and plug those little pollution ports below each of the exhaust ports. tmm
 
open chamber 318 heads that i have cc'd myself have all been 68cc's

the 302's i have here that i cc'd came out to the advertised 64cc's

u better measure them and not guess, im sure u'll be quite surprised at what they actually are..
 
Now that the head issue has been address, not solved, the intake I would use is the performer.
 
1wild&crazyguy said:
open chamber 318 heads that i have cc'd myself have all been 68cc's

the 302's i have here that i cc'd came out to the advertised 64cc's

u better measure them and not guess, im sure u'll be quite surprised at what they actually are..
Click to expand...

Thanks wild. Head cc is one of those things where you ask 10 people and may get 10 different answers and that is coming from mopar guys. This top end rebuild will just get me by until the 318 stroker is built. Just a cruiser, nothing more.
 
Badart said:
Thanks wild. Head cc is one of those things where you ask 10 people and may get 10 different answers and that is coming from mopar guys. This top end rebuild will just get me by until the 318 stroker is built. Just a cruiser, nothing more.
Click to expand...

its not hard to find out, got a measuring cup?lol

take a cd case half and drill a hole in it, grease around the edge of the chamber... then start pouring, carefully.


or u can get a kit like i did on ebay, then you do it easier and check all kinds of things like port volume, piston dish ...etc..
 
i didnt say anything on the intakes cause depending on gears...they both will work about the same .imo
the carb is great too...so not much to say.lol

have fun
 
Badart said:
70-72???? Never heard that before. Are you thinking of 360 heads?
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That info comes from the general information section of "How to Hot Rod Small Block Mopar Engines" by Larry Shepard.
It's stated that head casting 4027163 comes from 77-79 318s and has a cc of 64.5 to 71.5 so I roughed it to around 70. Most heads do fall into a range of CCs but when measuring it's not too often I come across any that aren't on the high end of the scale.
 
Thanks leadfoot. I thought that it would be lower. I will cc them the next couple of days and report back.
 
If those 4027163's vary from 64.5 to 70 cc's thats screwed up. Imagine those on a stock motor with that much variation! I have some 74 318's that checked out to 72cc's.
 
I saw 67 cc on a chart. Best to cc them to make sure. tmm
 
You may have to do some grinding under the driver's side rear exhaust port. The stock early manifolds have interference problems on some heads with the smog bosses. Don't grind the exhaust manifold or your asking for a crack. If it's just a cruiser, I wouldn't worry about the compression ratio too much. In fact, if it's a bit lower, you won't have pinging problems like the stock heads.
 
cudamark said:
You may have to do some grinding under the driver's side rear exhaust port. The stock early manifolds have interference problems on some heads with the smog bosses. Don't grind the exhaust manifold or your asking for a crack. If it's just a cruiser, I wouldn't worry about the compression ratio too much. In fact, if it's a bit lower, you won't have pinging problems like the stock heads.
Click to expand...


Right on! Thanks for the info. I love grinding.
 
CC'd the heads today and they are between 67-68cc, so I figure that if I use an .028 head gasket it should put me around 8.72:1 I think that I can live with that, but that is if the pistons are 0 decked. We will see.
 

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1wild&crazyguy said:
check both heads, those 596 heads are listed as 360 head, yet the 163 is a 318 head, according to casting charts i have.
Click to expand...

It's actually a 593 and is a 318 head listed as a 77-84 and the 163 is listed as a 77-86, but they are exactly the same other than the casting number. I figure it's no big deal. I noticed it when I picked them up, but you couldn't beat the price.
 
Started porting the 318 heads a little tonight. Sorry it's not the best pic too much light. Looks better already.
 

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