Getting worried-----
For what it's worth, I have a Lunati 60404 in the 340 in my Duster. The compression on my 340 works out to be 9.8:1 (static), which I came to after cc'ing the heads, calculating the head gasket volume, and talking to KB about the piston volume on the KB243's because of my early 340 putting the pistons .018" proud of the deck. According to the calculator the dynamic effective compression ratio is 8.195, and the cranking compression even with the 60404 is about 180 psi on my gauge.
The 60404 is quite a bit more cam than the 60401, I posted the cam card below for it's specs. With my iron 308 heads (ported, 2.02/1.60) I run 91 octane, and run the timing at 20* advanced at idle and 34* all in to prevent detonation. It pulls 9-10" vacuum at idle. I had to pull the timing back a couple degrees to keep it from detonating with the advance all in to run it with the less than great 91 octane here in California.
So, I would definitely calculate out the C/R and consider what the dynamic compression will be before I went with a 60401. More than likely the "10.5:1" pistons won't put you anywhere near 10.5:1 for your actual static compression ratio, but I would definitely check.
For what it's worth, I have a Lunati 60404 in the 340 in my Duster. The compression on my 340 works out to be 9.8:1 (static), which I came to after cc'ing the heads, calculating the head gasket volume, and talking to KB about the piston volume on the KB243's because of my early 340 putting the pistons .018" proud of the deck. According to the calculator the dynamic effective compression ratio is 8.195, and the cranking compression even with the 60404 is about 180 psi on my gauge.
The 60404 is quite a bit more cam than the 60401, I posted the cam card below for it's specs. With my iron 308 heads (ported, 2.02/1.60) I run 91 octane, and run the timing at 20* advanced at idle and 34* all in to prevent detonation. It pulls 9-10" vacuum at idle. I had to pull the timing back a couple degrees to keep it from detonating with the advance all in to run it with the less than great 91 octane here in California.
So, I would definitely calculate out the C/R and consider what the dynamic compression will be before I went with a 60401. More than likely the "10.5:1" pistons won't put you anywhere near 10.5:1 for your actual static compression ratio, but I would definitely check.