Mine weren't postulations, they were real live motors on the street. The 400 was an ok set up but the 351W setup was way better. Seems on stock production blocks, the older 71-73 block held together very well. 5.0's are kewl, til the first time you build one with a 347 stroker kit, then a 351W to 408, then the 427 stroker. Bigger is better!!! Monster torque and with the aluminum heads and intake a real lightweight motor too!!!!! The 5.0's become quite tame by comparison.