mdross1,
My E-M with the 521 just passed 30K street and track miles. The grin factor has been, and still is, enormous. Even with the C-6 auto and a 2.88 posi Jag rear, it is necessary to "roll on" the throttle at any speed. If you stomp it you can lose it in an instant, even with the wear rating 200 street tires. If you are on the track with Kumhos or similar slicks, you still need to be careful...
The engine has the newest Holley multiport EFI and a Crane hydraulic roller. I still think it's the most HP and torque available for the dollar, and if you pay attention to the
oil system updates here (particularly the distributor gear mod):
http://www.highflowdynamics.net you should have a very reliable engine as well.
I like it so much I built a 557 for my 1981 Zephyr wagon
That's my story...
Tom
PS: It took two D9 blocks to get a successful 4.440" (0.080 over) for the 557