440 head/compression help

[70challengerrt]

I have a 75 chrysler newport motor which according to the books it has 8.2 compression ratio. I have 452 head on it now.  I was considering going to edelbrock heads which have a cc of 84cc and 88cc. would I gain any compression? I know I could use a thinner head gasket like .020. I would like a finished compression ratio of 9.5-10.0. I can get a set of heads from a 413 motor which are closed chamber and would bump up my compression but I am leaning toward aluminum for the improved flow.

[EvilTwinATX]

I am in nearly the same situation.. from what I have found out here is a GENERAL GUIDELINE...(I am no expert. )
Zero deck your block and use the edlebrock heads 84CC (not 88cc). Use flat top pistons and adjust your compression by using a thicker, or thinner, head gasket....but in general you should be around 10-1 compression.

To be honest..there are a lot of guys who know more than me about this....  Engine Gurus???

[Chryco Psycho]

the stock head is 88 cc approx & can use the thin .020 head gaskets ,keep in mind that stock blocks usually have higher decks than speced so your real compression right now is closer to 7.8 :1
 all the below figures are based on 8.2 to start with & could be .4 lower   
the Eddy 84 cc will gain you .4 compression to a whopping 8.6 :1 but you need to use the Cometic head gasket with a minimum thickness of I think .030 & alum absorbs heat faster so you lose 1 point of compression so the net result will be approx 7.5:1 compression
 using closed chamber Iron heads are the best bet so far with a 1 point gain & using thin head gaskets you will net approx 9.3 :1   
 with an alum head you really need to gain approx 1.6 [or 2 if the real compression is now 7.8] points of compression so you need a combustion chamber in the 68-72 cc range to increase the compression to a workable 9.8 for pump gas , the Only alum head in that range is the B1-BS street head 

[Follicly Challenged]

CHRYCO, you forgot,
INDY "EZ" head also has a 75 cc chamber than can be cut .010" to yield the required 73.4 cc chamber if thats what you're after.
It also uses, stock valvetrain, Intake, headers etc. Stock exhaust port height and location.

[70challengerrt]

Just out of curiosity you don't know the total cylinder cc with the heads and stock gasket set which should be 4.410 gasket bore and .039 thick. I was using my computer dyno set up and when I enter the motor and the cylinder head specs, gasket specs it comes up with 9.7:1 compression. I know mine is not that high. Did the 75 motors use flat top pistons or did they have valve relief cuts or dished out? If so how many cc?

[EvilTwinATX]

the stock head is 88 cc approx & can use the thin .020 head gaskets ,keep in mind that stock blocks usually have higher decks than speced so your real compression right now is closer to 7.8 :1
 all the below figures are based on 8.2 to start with & could be .4 lower   
the Eddy 84 cc will gain you .4 compression to a whopping 8.6 :1 but you need to use the Cometic head gasket with a minimum thickness of I think .030 & alum absorbs heat faster so you lose 1 point of compression so the net result will be approx 7.5:1 compression
 using closed chamber Iron heads are the best bet so far with a 1 point gain & using thin head gaskets you will net approx 9.3 :1   
 with an alum head you really need to gain approx 1.6 [or 2 if the real compression is now 7.8] points of compression so you need a combustion chamber in the 68-72 cc range to increase the compression to a workable 9.8 for pump gas , the Only alum head in that range is the B1-BS street head 

Told ya'!  I am learnin'....

[Chryco Psycho]

Just out of curiosity you don't know the total cylinder cc with the heads and stock gasket set which should be 4.410 gasket bore and .039 thick. I was using my computer dyno set up and when I enter the motor and the cylinder head specs, gasket specs it comes up with 9.7:1 compression. I know mine is not that high. Did the 75 motors use flat top pistons or did they have valve relief cuts or dished out? If so how many cc?

they used a flat top piston but it was no where near flsh with the Deck of the block typically it was .100 or more down the hole