For those with vortec heads on a 305. i am putting my 062s on my 83 lg4 and i know that the vortecs are supposed to be milled .010 for use on 305 but i also want to use them on my next 350. can i use smaller head gaskets to bump CR up high enough to work. i did read some posts that said just use stock size head gaskets and it will be fine but i want to be sure. since i am going from 58cc chambers to 64ccs on low compression already. what size head gaskets to get.

 

Assuming the heads are flat, I would use the smallest thickness head gasket that is available. I'm thinking .005 if you can get away with it. You're gonna need all the help you can get using those heads.
Someone around here will have a formula for it, just keep checking.

 

64cc vortecs with a felpro 1094 .015" gasket should be around ~9.0:1 afaik.

milled

0.062" = 53cc with .015" gasket = 10.5:1
0.062" = 53cc with .039" gasket = 9.8:1
0.062" = 53cc with .051" gasket = 9.5:1

all on a 305


Nebu.

 

so if i use that felpro 1094 i should be okay with out modifiing anything and even bring my compression from 8.6:1 to 9:1. is there any downfalls to not milling the heads and just using a smaller gasket. i thought e remember reading that it wasnt the best route.

 

the point is, that the heads and the block have to be absolutely flat for use with such a thin gasket. however, i have not checked if my block is flat. just cleaned up the surface very good, coatet the gaskets with copperspray and havent had any problems so far...


nebu.

 

is there a thicker one i could use and still be above 8.6:1 or will the added thickness not be enough to save me if something wasnt 100% flat.