I am currently restoring a 1957 chevrolet 3200 pickup, causing the budget for engine work to be very tight, i.e. enough for vortec heads. I recently was gifted a 1975 chevrolet c20 it has a 165hp 350, upon measuring the bore the engine was never rebuilt and still has a 4.00 bore. Per my Motor's Manual from 1976 it shows this engine to have 8.5:1 compression ratio. The stock heads that came on the engine were 3998991 1.72 int/ 1.5 ex 76cc chambers. From two other 350's, I also have two other sets of heads casting #s 14022601 1.84 int/1.5 ex 53cc chambers and 462624 1.94 int/ 1.6 ex 76 cc chambers. From Mortech's website the heads I am leaning towards using 14022601 are supposedly for a 305. From what I have read the lower flow of these heads don't appear to pose an issue to me as this engine will rarely ever see revs higher than 4500 rpm as I am only planning to use the truck as a daily driver and occaisionally hauling atv's. I understand that with the stock pistons and the 14022601 heads will have a compression ratio of about 10:1. This seems a little high for pump gas, so I was thinking of using head gaskets that are .050" thick and a long duration cam like CompCams XE256H to help with cylinder pressure. I have already purchased an Edelbrock Performer RPM Airgap Intake and have and edelbrock 600CFM 4 barrel and a Holley 750CFM doublepumper. As I intend this for street use I am leaning towards using the Edelbrock as I fear the Double pumper will not be wallet friendly with 3.25/gal gas. Which way would you guys go on this  

Actually I meant not enough in the budget for Vortec heads  

IMO with the intake and cam you are planning on using I would hold out till I could afford the Vortecs