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Username Post: 348 Cylinder Heads        (Topic#350603)
Noel99 
Forum Newbie
Posts: 7

Age: 70
Loc: Ontario
Reg: 09-18-15
04-13-18 04:10 AM - Post#2730841    

Good Morning,
Need a little assistance with Cylinder Heads - I have a 348 Tri-Power (which I have had some good advice from Chevy Talk - thank you all). I have the opportunity to pick up rebuilt heads. I am purchasing from a person I have known for some time who I trust but I wanted to ask a couple of questions & get any feedback possible. My current heads are truck heads (#3764702). I expect it was originally a truck engine.
The Heads I may be purchasing are car heads (#3758379 (1959-61) & (#3781173 (1960)).The intake & exhaust ratios are the same. The HP rating is 250 on the 59-60 - can't locate the HP rating on the 60.

Is it ok to use heads from different years & with different #'s? Is there any other things I should be aware of here?

Anything you can tell me is greatly appreciated.

Noel



 
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DonSSDD 
Silver Supporting Member
Posts: 6745
DonSSDD
Loc: Nova Scotia, Canada
Reg: 08-21-01
04-13-18 05:39 PM - Post#2730891    
    In response to Noel99

You might want to ask this question on 348-409.com forums, and read this post.
http://www.348-409.com/forum/threads/348-hea d-ques...

63 Pontiac Parisienne Sport Coupe(CDN Chev mechanically (409, 4 speed),62 Bel Air SC (sold), 59 El Camino (sold), 62 Bel Air SC(sold), 63 SWC Vette (sold),
Member #2194


 
threeimpalas 
Senior Member
Posts: 1136

Loc: Central Iowa
Reg: 02-21-02
04-13-18 08:13 PM - Post#2730906    
    In response to Noel99

  • Noel99 Said:
Is it ok to use heads from different years & with different #'s? Is there any other things I should be aware of here?



Yes, you can interchange years and casting numbers.

For 348 heads on a 348 block, the only thing you'd need to be aware of is lack of spark-plug cooling passages on early 348 heads and blocks. If mixing early heads on a later block, or later heads on an early block, you will need to plug the open coolan passage.

Mike
'58-62s and 348/409s


 
DonSSDD 
Silver Supporting Member
Posts: 6745
DonSSDD
Loc: Nova Scotia, Canada
Reg: 08-21-01
04-14-18 08:49 AM - Post#2730947    
    In response to threeimpalas

  • threeimpalas Said:
  • Noel99 Said:
Is it ok to use heads from different years & with different #'s? Is there any other things I should be aware of here?



Yes, you can interchange years and casting numbers.

For 348 heads on a 348 block, the only thing you'd need to be aware of is lack of spark-plug cooling passages on early 348 heads and blocks. If mixing early heads on a later block, or later heads on an early block, you will need to plug the open coolan passage.



I would want them to be similar/the same for flow numbers and valve sizes. If one side is different than the other, you would have an unbalanced combustion/compression happening from one side of the block to the other?


63 Pontiac Parisienne Sport Coupe(CDN Chev mechanically (409, 4 speed),62 Bel Air SC (sold), 59 El Camino (sold), 62 Bel Air SC(sold), 63 SWC Vette (sold),
Member #2194


 
Gene_Schneider 
Ultra Senior Member
Posts: 12106

Loc: Wisconsin..USA
Reg: 09-27-02
04-14-18 03:53 PM - Post#2730982    
    In response to Noel99

On a 348 the heads do not determine the compression ratio.....the pistons do.
The head is flat with no combustion chamber.....the combustion chamber is in the piston.

ChevGene 1934 Master sedan 1939 Master DeLuxe Town Sedan 1950 Styline DeLuxe Power Glide 1957 Nomad 283 PG 1963 Corvair Convertible


Edited by Gene_Schneider on 04-14-18 03:57 PM. Reason for edit: No reason given.

 
Noel99 
Forum Newbie
Posts: 7

Age: 70
Loc: Ontario
Reg: 09-18-15
04-15-18 08:37 AM - Post#2731026    
    In response to Gene_Schneider

Thanks to all for your info. There is always too much info for a novice such as myself to completely understand. It is interesting that the 1173 head is a little bit of a mystery.

What I have gleaned thus far is:

Yes I can use different numbered heads together & be aware of the spark plug coolant passages.

This is sufficient info for me to go forward at this point.

Once again thank you all for your input.

Noel




 
threeimpalas 
Senior Member
Posts: 1136

Loc: Central Iowa
Reg: 02-21-02
04-15-18 09:06 PM - Post#2731119    
    In response to DonSSDD

  • DonSSDD Said:
I would want them to be similar/the same for flow numbers and valve sizes.



The 1173 is supposedly the service replacement head for the 379, in which case it would have the same ports and valve sizes.

Since they've been rebuilt, once would assume they have had the valve springs replaced and are the same as each other.

Mike
'58-62s and 348/409s


 
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