How much can this block handle based on the sonic check results?

[Bobbie Burke]

I have a 470 in my 70 Coronet that I built in 2002. It's a pretty mild build (238/244 hydraulic cam, ported 452 heads, 10:1 compression), but it needs a refresh so I was going to possibly throw in a 4.25" stroke crank and some Trick Flow heads and go for 650 hp or so. I just found the sonic check results for the block from 2002 and I'm not sure the numbers look very good based on what I've been reading. How much power/torque should this particular block be able to handle? (it's a 1971 400 block, 230 casting) Should I start scouring junkyards to find a better example or will this thing be OK?

Thanks,
-Bobbie

 

[Rusty 72]

Seeing the results are that old I would have it rechecked. Technology has come a long was since 2002.
Just my $0.02

 

[67MPRFAN]

Why not add the trick flow and upgrade the cam on the 470 during refresh ... Just wondering because I'm going to finish my 470 build and hope to be close to 650hp unless it's torque from the bigger motor you want just curious that's all

 

[Bobbie Burke]

Why not add the trick flow and upgrade the cam on the 470 during refresh ... Just wondering because I'm going to finish my 470 build and hope to be close to 650hp unless it's torque from the bigger motor you want just curious that's all

I may end up sticking with the 470. One issue is I currently have flat top pistons which would push the CR over 11:1 with Truck Flow heads and I can't find any dished pistons that have the right compression height for my 6.385" rods. Another issue is I'm running a cut down OEM 440 crank and I had heard they don't hold well to 600+ horsepower. I figure if I need crank rods and pistons I might as well go bigger to keep the converter and gearing more mild. I'm just wondering if this is the right block for this plan.