No, I didn't install the roll pins. I don't have a motor plate. The SBC mounts in the front as normal, and uses a stock type mount on the trans. I install the engine and trans as an assembly into the car. I ran a used Muncie 4 speed until it began popping out of gear last October. Over the winter I bought a new Autogear trans which is a Muncie knock off. In April I ran the car on a chassis dyno, and it popped out of gear, I have chased this problem for a year. Over the coarse of the year I have changed the 3rd member, driveshaft, transmission, clutch, pressure plate, flywheel, pilot bushing, throwout bearing, bellhousing, and had torque lock slider syncros installed in the trans, bought a new old stock Hurst Shifter, and removed the solid front and rear motor mounts, and installed polyurethane. Turned the motor upside down on a stand and inspected the bearings, looked at the connecting rods etc. The motor is a wet sump retired circle track 359 cu in that I re-cammed. It makes 644 horse at 7600 rpm. I am not a contender for a red hat, just an old guy who has family camp outs, and runs the car for bragging rights. My son ran the car through at 181.466 mph in September 2016 El Mirage, and in October this crap started. Somebody suggested I put a big block and a turbo 400 auto trans in it. Maybe I should, but I haven't given up my small block yet. I installed the engine and trans today in 100 degree So Cal heat, in anticipation of October El Mirage. We'll soon see if the bellhousing related work has helped. Thanks Terry...