Need SERIOUS opinons and quickly!

That would be a VERY high compresion shortblock, as the pics look as though they are domed pistons. Without knowing the exact details on the pistons, what machine work was done, etc I'd stay away from it.
 
306 doesnt make any more power than a 302 unless your talking about changing comp. and cam timing. or you stroke it but that is actually adding more cubes by way of stoke. but if you have engine problems now then you might want to freshen up the motor bore it over .30 and but some better piston in there
 
yobi1kanobi said:
306 doesnt make any more power than a 302 unless your talking about changing comp. and cam timing. or you stroke it but that is actually adding more cubes by way of stoke. but if you have engine problems now then you might want to freshen up the motor bore it over .30 and but some better piston in there


Boring it .030" over also helps to unshroud the valve and improve airflow into the cylinder, and that DOES aid in power production especially when a larger than stock sized valve is used.