how well will 340 x heads work with my 318?

[440charger68]

The motor is a 68 318 with a new cam 492 lift edelbrock air gap and a 650cfm carb and im about to pic up some 340 x heads in a few hours i wanted to see if u guys think if this would be a good way to increase hp and compression and the heads were only 275$ is it a good deal? and how much of a power increase or decrease?

[Challenger340]

Simple answer with no other changes;
Power Decrease on a 318, due to Compression Ratio Loss, as the 340 Heads Have a Larger Chamber.

$275. for 340 X Heads is a good buy though.

[oldkimmer]

............U will  loose over 1 comp point..........thats 2 big of a cam 4 ur 318.......it will b pretty sad without a 3500 stall.......kim..........