Ole Johnny Male, Kristiansund Norway, 1969 Dodge Dart 2 drht (GTS replica) 340

Hey Rick!

I am a guy from Norway, who has subscribed to MOPAR ACTION for years. I'm driving a 69 Dart GTS (replica)with a 340 engine. The engine is std. except the cam, which is replaced with a Crower cam, 282 deg., and an a Edelbrock performer RPM intake. The car is built for street/strip with a narrowed 8-3/4" rear, 4,10 gear, and S/S springs. EsThe car go steady 8.5s on 1/8 mile and 13.00 1/4 mile, but now I want to go faster. So here is my question: I have an offer on a race small block Mopar. It seems to be a race block but I'm not sure. The casting nr .is 4104230-318-6 built date 5-14-79. In my books that casting nr. is a std. 318 but this block has the X cast in on the right front. And it has 4 bolt mains and solid pan rails. So what kind of block is this? And how much can it be overbored? Now it has std.340 bore, 4.04". I hope you can help me with this thing, because im not sure about this block.