I have been going back and forth and since I am in no hurry thought I would post to see what others thought. I have a 4 bolt 400 that had been decked, bored 30 over, the mains line bored and all the usual stuff. It had forged pistons and some dart replacement heads that had some mild porting with a fairly large hydraulic cam. The problem was that the cam wiped a few lobes (most likely due to the heavy springs and improper break in) and instead of being taken out of service was left in the car for some time. Needless to say it was driven hard and put away wet! Now some 10 years later I decide to tear it down with the wishful thinking I could reuse the pistons and such with out boring it any further. I knew it would need new bearings and such but instead the cylinder walls will need a 40 over to clean them up. I will now need a complete rotating assembly. I wouldn’t normally go 40 over on a 400 but the machine shop feels it will be fine since it will be used mostly on the street and will not be seeing any nitrous etc. I want to upgrade the heads to some AFR 210 with a hydraulic roller. I would like to keep the RPM at or below 7000. What I am going back and forth on is if I want to sink any money in this block when I could be putting it into say a dart block and turning it into say a 434. I know that the dart block with a forged crank / 4340 h beam rods and such would be much more expensive but the reliability and foundation for more would be there when and if I needed. On the other hand I have used plenty a stock cast cranks and less expensive parts and never had a problem running them hard on the street. This will be the first time I want to build some real power that wasn’t your average 400 – 450 horse engine. So what would you do, put it towards the dart or just polish the turd so to speak and build off it?