The R/T has stock crank and rods with Keith Black 30 over pistons. I just put my 906s back on because I had a retainer failure on my Eddy's but luckily I only bent a valve. Also has a wiand single plane intake with an 850 mighty demon carb. 3.55s in the 8 3/4 but looking into reworking a truck dana I found close by. Car runs mid 12s at 108 mph. I haven't run it at the track yet but will soon. The 906s have stock size valves but are heavily ported and the Eddy's had larger valves but used ootb. Looking forward to see the difference in performance with no other changes.