Pontiac Head Help needed !!

I have a 1972 400 GTO motor with 7K3 heads. I want more power and was thinking of changing the heads , cam etc..  My question is can I just put a set of 1968 #62 heads or 1968 #15 heads on my block. Will the compression change that much ? Will it be worth it money and HP wise. I chose these as thet are both available locally. Lastly are the Edelbrock heads that much different than the ones I listed above. thanks for your time
                                                                                                                                                             Rick  

With the #15 heads you would actually lose power because they have the smaller valves and with the #62 heads you would have too much compression to run pump gas.
The edelbrock heads are better then all three heads you listed above they flow better and you can run higher compression with aluminum heads on pump gas.

What is the specs on the cam you have now?  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

With the #15 heads you would actually lose power because they have the smaller valves and with the #62 heads you would have too much compression to run pump gas.
The edelbrock heads are better then all three heads you listed above they flow better and you can run higher compression with aluminum heads on pump gas.

What is the specs on the cam you have now?  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Thats too bad about the #62 heads as I could get them fairly cheap. The specs on the cam are 292 / 490 by Lunati. What do you think.  

The no.62 heads would put you at over 10:1 compression, too much for pump gas. You'd either need to run dished pistons with them, have the combustion chambers opened up to 82 cc to put your compression below 9.5:1.

If either of these options don't intimidate you and you can pick the heads up for a decent price, do it. 72cc D-ports like the no.62 are good performance heads (2.11/1.77 valves, screw-in studs) and respond well to proper porting (240-250 cfm). I opened up the chambers on both no.13 and no.48 heads I have, and can run them with pump gas when either set is on a 400.

Geno